diff --git a/.babelrc b/.babelrc
index 0558174..84f1630 100644
--- a/.babelrc
+++ b/.babelrc
@@ -1,3 +1,10 @@
 {
-  "presets": ["es2015", "stage-2"]
+  "presets": [
+    ["env", {
+      "targets": {
+        "node": 4
+      }
+    }],
+    "stage-2"
+  ]
 }
diff --git a/package.json b/package.json
index efe45f2..72236c3 100644
--- a/package.json
+++ b/package.json
@@ -41,7 +41,7 @@
     "babel-eslint": "^7.1.1",
     "babel-jest": "^18.0.0",
     "babel-plugin-module-resolver": "^2.5.0",
-    "babel-preset-es2015": "^6.22.0",
+    "babel-preset-env": "^1.1.8",
     "babel-preset-stage-2": "^6.22.0",
     "babel-register": "^6.22.0",
     "cli-tester": "^2.0.0",
diff --git a/yarn.lock b/yarn.lock
index cb88280..c4f9db5 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -490,7 +490,7 @@ babel-messages@^6.22.0:
   dependencies:
     babel-runtime "^6.22.0"
 
-babel-plugin-check-es2015-constants@^6.22.0:
+babel-plugin-check-es2015-constants@^6.3.13:
   version "6.22.0"
   resolved "https://registry.yarnpkg.com/babel-plugin-check-es2015-constants/-/babel-plugin-check-es2015-constants-6.22.0.tgz#35157b101426fd2ffd3da3f75c7d1e91835bbf8a"
   dependencies:
@@ -545,7 +545,7 @@ babel-plugin-syntax-object-rest-spread@^6.8.0:
   version "6.13.0"
   resolved "https://registry.yarnpkg.com/babel-plugin-syntax-object-rest-spread/-/babel-plugin-syntax-object-rest-spread-6.13.0.tgz#fd6536f2bce13836ffa3a5458c4903a597bb3bf5"
 
-babel-plugin-syntax-trailing-function-commas@^6.22.0:
+babel-plugin-syntax-trailing-function-commas@^6.13.0, babel-plugin-syntax-trailing-function-commas@^6.22.0:
   version "6.22.0"
   resolved "https://registry.yarnpkg.com/babel-plugin-syntax-trailing-function-commas/-/babel-plugin-syntax-trailing-function-commas-6.22.0.tgz#ba0360937f8d06e40180a43fe0d5616fff532cf3"
 
@@ -557,7 +557,7 @@ babel-plugin-transform-async-generator-functions@^6.22.0:
     babel-plugin-syntax-async-generators "^6.5.0"
     babel-runtime "^6.22.0"
 
-babel-plugin-transform-async-to-generator@^6.22.0:
+babel-plugin-transform-async-to-generator@^6.22.0, babel-plugin-transform-async-to-generator@^6.8.0:
   version "6.22.0"
   resolved "https://registry.yarnpkg.com/babel-plugin-transform-async-to-generator/-/babel-plugin-transform-async-to-generator-6.22.0.tgz#194b6938ec195ad36efc4c33a971acf00d8cd35e"
   dependencies:
@@ -584,19 +584,19 @@ babel-plugin-transform-decorators@^6.22.0:
     babel-template "^6.22.0"
     babel-types "^6.22.0"
 
-babel-plugin-transform-es2015-arrow-functions@^6.22.0:
+babel-plugin-transform-es2015-arrow-functions@^6.3.13:
   version "6.22.0"
   resolved "https://registry.yarnpkg.com/babel-plugin-transform-es2015-arrow-functions/-/babel-plugin-transform-es2015-arrow-functions-6.22.0.tgz#452692cb711d5f79dc7f85e440ce41b9f244d221"
   dependencies:
     babel-runtime "^6.22.0"
 
-babel-plugin-transform-es2015-block-scoped-functions@^6.22.0:
+babel-plugin-transform-es2015-block-scoped-functions@^6.3.13:
   version "6.22.0"
   resolved "https://registry.yarnpkg.com/babel-plugin-transform-es2015-block-scoped-functions/-/babel-plugin-transform-es2015-block-scoped-functions-6.22.0.tgz#bbc51b49f964d70cb8d8e0b94e820246ce3a6141"
   dependencies:
     babel-runtime "^6.22.0"
 
-babel-plugin-transform-es2015-block-scoping@^6.22.0:
+babel-plugin-transform-es2015-block-scoping@^6.6.0:
   version "6.22.0"
   resolved "https://registry.yarnpkg.com/babel-plugin-transform-es2015-block-scoping/-/babel-plugin-transform-es2015-block-scoping-6.22.0.tgz#00d6e3a0bebdcfe7536b9d653b44a9141e63e47e"
   dependencies:
@@ -606,7 +606,7 @@ babel-plugin-transform-es2015-block-scoping@^6.22.0:
     babel-types "^6.22.0"
     lodash "^4.2.0"
 
-babel-plugin-transform-es2015-classes@^6.22.0:
+babel-plugin-transform-es2015-classes@^6.6.0:
   version "6.22.0"
   resolved "https://registry.yarnpkg.com/babel-plugin-transform-es2015-classes/-/babel-plugin-transform-es2015-classes-6.22.0.tgz#54d44998fd823d9dca15292324161c331c1b6f14"
   dependencies:
@@ -620,33 +620,33 @@ babel-plugin-transform-es2015-classes@^6.22.0:
     babel-traverse "^6.22.0"
     babel-types "^6.22.0"
 
-babel-plugin-transform-es2015-computed-properties@^6.22.0:
+babel-plugin-transform-es2015-computed-properties@^6.3.13:
   version "6.22.0"
   resolved "https://registry.yarnpkg.com/babel-plugin-transform-es2015-computed-properties/-/babel-plugin-transform-es2015-computed-properties-6.22.0.tgz#7c383e9629bba4820c11b0425bdd6290f7f057e7"
   dependencies:
     babel-runtime "^6.22.0"
     babel-template "^6.22.0"
 
-babel-plugin-transform-es2015-destructuring@^6.22.0:
+babel-plugin-transform-es2015-destructuring@^6.6.0:
   version "6.22.0"
   resolved "https://registry.yarnpkg.com/babel-plugin-transform-es2015-destructuring/-/babel-plugin-transform-es2015-destructuring-6.22.0.tgz#8e0af2f885a0b2cf999d47c4c1dd23ce88cfa4c6"
   dependencies:
     babel-runtime "^6.22.0"
 
-babel-plugin-transform-es2015-duplicate-keys@^6.22.0:
+babel-plugin-transform-es2015-duplicate-keys@^6.6.0:
   version "6.22.0"
   resolved "https://registry.yarnpkg.com/babel-plugin-transform-es2015-duplicate-keys/-/babel-plugin-transform-es2015-duplicate-keys-6.22.0.tgz#672397031c21610d72dd2bbb0ba9fb6277e1c36b"
   dependencies:
     babel-runtime "^6.22.0"
     babel-types "^6.22.0"
 
-babel-plugin-transform-es2015-for-of@^6.22.0:
+babel-plugin-transform-es2015-for-of@^6.6.0:
   version "6.22.0"
   resolved "https://registry.yarnpkg.com/babel-plugin-transform-es2015-for-of/-/babel-plugin-transform-es2015-for-of-6.22.0.tgz#180467ad63aeea592a1caeee4bf1c8b3e2616265"
   dependencies:
     babel-runtime "^6.22.0"
 
-babel-plugin-transform-es2015-function-name@^6.22.0:
+babel-plugin-transform-es2015-function-name@^6.3.13:
   version "6.22.0"
   resolved "https://registry.yarnpkg.com/babel-plugin-transform-es2015-function-name/-/babel-plugin-transform-es2015-function-name-6.22.0.tgz#f5fcc8b09093f9a23c76ac3d9e392c3ec4b77104"
   dependencies:
@@ -654,13 +654,13 @@ babel-plugin-transform-es2015-function-name@^6.22.0:
     babel-runtime "^6.22.0"
     babel-types "^6.22.0"
 
-babel-plugin-transform-es2015-literals@^6.22.0:
+babel-plugin-transform-es2015-literals@^6.3.13:
   version "6.22.0"
   resolved "https://registry.yarnpkg.com/babel-plugin-transform-es2015-literals/-/babel-plugin-transform-es2015-literals-6.22.0.tgz#4f54a02d6cd66cf915280019a31d31925377ca2e"
   dependencies:
     babel-runtime "^6.22.0"
 
-babel-plugin-transform-es2015-modules-amd@^6.22.0:
+babel-plugin-transform-es2015-modules-amd@^6.22.0, babel-plugin-transform-es2015-modules-amd@^6.8.0:
   version "6.22.0"
   resolved "https://registry.yarnpkg.com/babel-plugin-transform-es2015-modules-amd/-/babel-plugin-transform-es2015-modules-amd-6.22.0.tgz#bf69cd34889a41c33d90dfb740e0091ccff52f21"
   dependencies:
@@ -668,7 +668,7 @@ babel-plugin-transform-es2015-modules-amd@^6.22.0:
     babel-runtime "^6.22.0"
     babel-template "^6.22.0"
 
-babel-plugin-transform-es2015-modules-commonjs@^6.22.0:
+babel-plugin-transform-es2015-modules-commonjs@^6.22.0, babel-plugin-transform-es2015-modules-commonjs@^6.6.0:
   version "6.22.0"
   resolved "https://registry.yarnpkg.com/babel-plugin-transform-es2015-modules-commonjs/-/babel-plugin-transform-es2015-modules-commonjs-6.22.0.tgz#6ca04e22b8e214fb50169730657e7a07dc941145"
   dependencies:
@@ -677,7 +677,7 @@ babel-plugin-transform-es2015-modules-commonjs@^6.22.0:
     babel-template "^6.22.0"
     babel-types "^6.22.0"
 
-babel-plugin-transform-es2015-modules-systemjs@^6.22.0:
+babel-plugin-transform-es2015-modules-systemjs@^6.12.0:
   version "6.22.0"
   resolved "https://registry.yarnpkg.com/babel-plugin-transform-es2015-modules-systemjs/-/babel-plugin-transform-es2015-modules-systemjs-6.22.0.tgz#810cd0cd025a08383b84236b92c6e31f88e644ad"
   dependencies:
@@ -685,7 +685,7 @@ babel-plugin-transform-es2015-modules-systemjs@^6.22.0:
     babel-runtime "^6.22.0"
     babel-template "^6.22.0"
 
-babel-plugin-transform-es2015-modules-umd@^6.22.0:
+babel-plugin-transform-es2015-modules-umd@^6.12.0:
   version "6.22.0"
   resolved "https://registry.yarnpkg.com/babel-plugin-transform-es2015-modules-umd/-/babel-plugin-transform-es2015-modules-umd-6.22.0.tgz#60d0ba3bd23258719c64391d9bf492d648dc0fae"
   dependencies:
@@ -693,14 +693,14 @@ babel-plugin-transform-es2015-modules-umd@^6.22.0:
     babel-runtime "^6.22.0"
     babel-template "^6.22.0"
 
-babel-plugin-transform-es2015-object-super@^6.22.0:
+babel-plugin-transform-es2015-object-super@^6.3.13:
   version "6.22.0"
   resolved "https://registry.yarnpkg.com/babel-plugin-transform-es2015-object-super/-/babel-plugin-transform-es2015-object-super-6.22.0.tgz#daa60e114a042ea769dd53fe528fc82311eb98fc"
   dependencies:
     babel-helper-replace-supers "^6.22.0"
     babel-runtime "^6.22.0"
 
-babel-plugin-transform-es2015-parameters@^6.22.0:
+babel-plugin-transform-es2015-parameters@^6.6.0:
   version "6.22.0"
   resolved "https://registry.yarnpkg.com/babel-plugin-transform-es2015-parameters/-/babel-plugin-transform-es2015-parameters-6.22.0.tgz#57076069232019094f27da8c68bb7162fe208dbb"
   dependencies:
@@ -711,20 +711,20 @@ babel-plugin-transform-es2015-parameters@^6.22.0:
     babel-traverse "^6.22.0"
     babel-types "^6.22.0"
 
-babel-plugin-transform-es2015-shorthand-properties@^6.22.0:
+babel-plugin-transform-es2015-shorthand-properties@^6.3.13:
   version "6.22.0"
   resolved "https://registry.yarnpkg.com/babel-plugin-transform-es2015-shorthand-properties/-/babel-plugin-transform-es2015-shorthand-properties-6.22.0.tgz#8ba776e0affaa60bff21e921403b8a652a2ff723"
   dependencies:
     babel-runtime "^6.22.0"
     babel-types "^6.22.0"
 
-babel-plugin-transform-es2015-spread@^6.22.0:
+babel-plugin-transform-es2015-spread@^6.3.13:
   version "6.22.0"
   resolved "https://registry.yarnpkg.com/babel-plugin-transform-es2015-spread/-/babel-plugin-transform-es2015-spread-6.22.0.tgz#d6d68a99f89aedc4536c81a542e8dd9f1746f8d1"
   dependencies:
     babel-runtime "^6.22.0"
 
-babel-plugin-transform-es2015-sticky-regex@^6.22.0:
+babel-plugin-transform-es2015-sticky-regex@^6.3.13:
   version "6.22.0"
   resolved "https://registry.yarnpkg.com/babel-plugin-transform-es2015-sticky-regex/-/babel-plugin-transform-es2015-sticky-regex-6.22.0.tgz#ab316829e866ee3f4b9eb96939757d19a5bc4593"
   dependencies:
@@ -732,19 +732,19 @@ babel-plugin-transform-es2015-sticky-regex@^6.22.0:
     babel-runtime "^6.22.0"
     babel-types "^6.22.0"
 
-babel-plugin-transform-es2015-template-literals@^6.22.0:
+babel-plugin-transform-es2015-template-literals@^6.6.0:
   version "6.22.0"
   resolved "https://registry.yarnpkg.com/babel-plugin-transform-es2015-template-literals/-/babel-plugin-transform-es2015-template-literals-6.22.0.tgz#a84b3450f7e9f8f1f6839d6d687da84bb1236d8d"
   dependencies:
     babel-runtime "^6.22.0"
 
-babel-plugin-transform-es2015-typeof-symbol@^6.22.0:
+babel-plugin-transform-es2015-typeof-symbol@^6.6.0:
   version "6.22.0"
   resolved "https://registry.yarnpkg.com/babel-plugin-transform-es2015-typeof-symbol/-/babel-plugin-transform-es2015-typeof-symbol-6.22.0.tgz#87faf2336d3b6a97f68c4d906b0cd0edeae676e1"
   dependencies:
     babel-runtime "^6.22.0"
 
-babel-plugin-transform-es2015-unicode-regex@^6.22.0:
+babel-plugin-transform-es2015-unicode-regex@^6.3.13:
   version "6.22.0"
   resolved "https://registry.yarnpkg.com/babel-plugin-transform-es2015-unicode-regex/-/babel-plugin-transform-es2015-unicode-regex-6.22.0.tgz#8d9cc27e7ee1decfe65454fb986452a04a613d20"
   dependencies:
@@ -752,7 +752,7 @@ babel-plugin-transform-es2015-unicode-regex@^6.22.0:
     babel-runtime "^6.22.0"
     regexpu-core "^2.0.0"
 
-babel-plugin-transform-exponentiation-operator@^6.22.0:
+babel-plugin-transform-exponentiation-operator@^6.22.0, babel-plugin-transform-exponentiation-operator@^6.8.0:
   version "6.22.0"
   resolved "https://registry.yarnpkg.com/babel-plugin-transform-exponentiation-operator/-/babel-plugin-transform-exponentiation-operator-6.22.0.tgz#d57c8335281918e54ef053118ce6eb108468084d"
   dependencies:
@@ -767,7 +767,7 @@ babel-plugin-transform-object-rest-spread@^6.22.0:
     babel-plugin-syntax-object-rest-spread "^6.8.0"
     babel-runtime "^6.22.0"
 
-babel-plugin-transform-regenerator@^6.22.0:
+babel-plugin-transform-regenerator@^6.6.0:
   version "6.22.0"
   resolved "https://registry.yarnpkg.com/babel-plugin-transform-regenerator/-/babel-plugin-transform-regenerator-6.22.0.tgz#65740593a319c44522157538d690b84094617ea6"
   dependencies:
@@ -788,34 +788,38 @@ babel-polyfill@^6.16.0, babel-polyfill@^6.22.0:
     core-js "^2.4.0"
     regenerator-runtime "^0.10.0"
 
-babel-preset-es2015@^6.22.0:
-  version "6.22.0"
-  resolved "https://registry.yarnpkg.com/babel-preset-es2015/-/babel-preset-es2015-6.22.0.tgz#af5a98ecb35eb8af764ad8a5a05eb36dc4386835"
-  dependencies:
-    babel-plugin-check-es2015-constants "^6.22.0"
-    babel-plugin-transform-es2015-arrow-functions "^6.22.0"
-    babel-plugin-transform-es2015-block-scoped-functions "^6.22.0"
-    babel-plugin-transform-es2015-block-scoping "^6.22.0"
-    babel-plugin-transform-es2015-classes "^6.22.0"
-    babel-plugin-transform-es2015-computed-properties "^6.22.0"
-    babel-plugin-transform-es2015-destructuring "^6.22.0"
-    babel-plugin-transform-es2015-duplicate-keys "^6.22.0"
-    babel-plugin-transform-es2015-for-of "^6.22.0"
-    babel-plugin-transform-es2015-function-name "^6.22.0"
-    babel-plugin-transform-es2015-literals "^6.22.0"
-    babel-plugin-transform-es2015-modules-amd "^6.22.0"
-    babel-plugin-transform-es2015-modules-commonjs "^6.22.0"
-    babel-plugin-transform-es2015-modules-systemjs "^6.22.0"
-    babel-plugin-transform-es2015-modules-umd "^6.22.0"
-    babel-plugin-transform-es2015-object-super "^6.22.0"
-    babel-plugin-transform-es2015-parameters "^6.22.0"
-    babel-plugin-transform-es2015-shorthand-properties "^6.22.0"
-    babel-plugin-transform-es2015-spread "^6.22.0"
-    babel-plugin-transform-es2015-sticky-regex "^6.22.0"
-    babel-plugin-transform-es2015-template-literals "^6.22.0"
-    babel-plugin-transform-es2015-typeof-symbol "^6.22.0"
-    babel-plugin-transform-es2015-unicode-regex "^6.22.0"
-    babel-plugin-transform-regenerator "^6.22.0"
+babel-preset-env@^1.1.8:
+  version "1.1.8"
+  resolved "https://registry.yarnpkg.com/babel-preset-env/-/babel-preset-env-1.1.8.tgz#c46734c6233c3f87d177513773db3cf3c1758aaa"
+  dependencies:
+    babel-plugin-check-es2015-constants "^6.3.13"
+    babel-plugin-syntax-trailing-function-commas "^6.13.0"
+    babel-plugin-transform-async-to-generator "^6.8.0"
+    babel-plugin-transform-es2015-arrow-functions "^6.3.13"
+    babel-plugin-transform-es2015-block-scoped-functions "^6.3.13"
+    babel-plugin-transform-es2015-block-scoping "^6.6.0"
+    babel-plugin-transform-es2015-classes "^6.6.0"
+    babel-plugin-transform-es2015-computed-properties "^6.3.13"
+    babel-plugin-transform-es2015-destructuring "^6.6.0"
+    babel-plugin-transform-es2015-duplicate-keys "^6.6.0"
+    babel-plugin-transform-es2015-for-of "^6.6.0"
+    babel-plugin-transform-es2015-function-name "^6.3.13"
+    babel-plugin-transform-es2015-literals "^6.3.13"
+    babel-plugin-transform-es2015-modules-amd "^6.8.0"
+    babel-plugin-transform-es2015-modules-commonjs "^6.6.0"
+    babel-plugin-transform-es2015-modules-systemjs "^6.12.0"
+    babel-plugin-transform-es2015-modules-umd "^6.12.0"
+    babel-plugin-transform-es2015-object-super "^6.3.13"
+    babel-plugin-transform-es2015-parameters "^6.6.0"
+    babel-plugin-transform-es2015-shorthand-properties "^6.3.13"
+    babel-plugin-transform-es2015-spread "^6.3.13"
+    babel-plugin-transform-es2015-sticky-regex "^6.3.13"
+    babel-plugin-transform-es2015-template-literals "^6.6.0"
+    babel-plugin-transform-es2015-typeof-symbol "^6.6.0"
+    babel-plugin-transform-es2015-unicode-regex "^6.3.13"
+    babel-plugin-transform-exponentiation-operator "^6.8.0"
+    babel-plugin-transform-regenerator "^6.6.0"
+    browserslist "^1.4.0"
 
 babel-preset-jest@^18.0.0:
   version "18.0.0"
@@ -1032,6 +1036,13 @@ browserify-zlib@^0.1.4:
   dependencies:
     pako "~0.2.0"
 
+browserslist@^1.4.0:
+  version "1.7.1"
+  resolved "https://registry.yarnpkg.com/browserslist/-/browserslist-1.7.1.tgz#cc9bd193979a2a4b09fdb3df6003fefe48ccefe1"
+  dependencies:
+    caniuse-db "^1.0.30000617"
+    electron-to-chromium "^1.2.1"
+
 bser@1.0.2:
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/bser/-/bser-1.0.2.tgz#381116970b2a6deea5646dd15dd7278444b56169"
@@ -1101,6 +1112,10 @@ camelcase@^3.0.0:
   version "3.0.0"
   resolved "https://registry.yarnpkg.com/camelcase/-/camelcase-3.0.0.tgz#32fc4b9fcdaf845fcdf7e73bb97cac2261f0ab0a"
 
+caniuse-db@^1.0.30000617:
+  version "1.0.30000622"
+  resolved "https://registry.yarnpkg.com/caniuse-db/-/caniuse-db-1.0.30000622.tgz#9d9690b577384990a58e33ebb903a14da735e5fd"
+
 cardinal@^1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/cardinal/-/cardinal-1.0.0.tgz#50e21c1b0aa37729f9377def196b5a9cec932ee9"
@@ -1610,6 +1625,10 @@ ecc-jsbn@~0.1.1:
   dependencies:
     jsbn "~0.1.0"
 
+electron-to-chromium@^1.2.1:
+  version "1.2.2"
+  resolved "https://registry.yarnpkg.com/electron-to-chromium/-/electron-to-chromium-1.2.2.tgz#e41bc9488c88e3cfa1e94bde28e8420d7d47c47c"
+
 elliptic@^6.0.0:
   version "6.3.3"
   resolved "https://registry.yarnpkg.com/elliptic/-/elliptic-6.3.3.tgz#5482d9646d54bcb89fd7d994fc9e2e9568876e3f"