fix(ssl): bump minimum supported node version to 4.5

BREAKING CHANGE: drop support for node 4 < 4.5
closes #176
- node versions 4.2 - 4.4 have a bug in the buffer implementation that
causes the ssl setup to fail

package.json

@@ -33,7 +33,7 @@
     "test": "yarn run lint && yarn run test:all"
   },
   "engines": {
-    "node": "^4.2.0 || ^6.5.0"
+    "node": "^4.5.0 || ^6.5.0"
   },
   "preferGlobal": true,
   "dependencies": {