diff --git a/package-lock.json b/package-lock.json
index e01de19..b2a257d 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -67,7 +67,8 @@
     "assert-plus": {
       "version": "1.0.0",
       "resolved": "https://registry.npmjs.org/assert-plus/-/assert-plus-1.0.0.tgz",
-      "integrity": "sha1-8S4PPF13sLHN2RRpQuTpbB5N1SU="
+      "integrity": "sha1-8S4PPF13sLHN2RRpQuTpbB5N1SU=",
+      "optional": true
     },
     "async-limiter": {
       "version": "1.0.1",
@@ -214,6 +215,7 @@
       "version": "1.0.8",
       "resolved": "https://registry.npmjs.org/combined-stream/-/combined-stream-1.0.8.tgz",
       "integrity": "sha512-FQN4MRfuJeHf7cBbBMJFXhKSDq+2kAArBlmRBvcvFE5BB1HZKXtSFASDhdlz9zOYwxh8lDdnvmMOe/+5cdoEdg==",
+      "optional": true,
       "requires": {
         "delayed-stream": "~1.0.0"
       }
@@ -310,7 +312,8 @@
     "delayed-stream": {
       "version": "1.0.0",
       "resolved": "https://registry.npmjs.org/delayed-stream/-/delayed-stream-1.0.0.tgz",
-      "integrity": "sha1-3zrhmayt+31ECqrgsp4icrJOxhk="
+      "integrity": "sha1-3zrhmayt+31ECqrgsp4icrJOxhk=",
+      "optional": true
     },
     "dom-serializer": {
       "version": "0.1.1",
@@ -416,7 +419,8 @@
     "extsprintf": {
       "version": "1.3.0",
       "resolved": "https://registry.npmjs.org/extsprintf/-/extsprintf-1.3.0.tgz",
-      "integrity": "sha1-lpGEQOMEGnpBT4xS48V06zw+HgU="
+      "integrity": "sha1-lpGEQOMEGnpBT4xS48V06zw+HgU=",
+      "optional": true
     },
     "fast-deep-equal": {
       "version": "2.0.1",
@@ -703,7 +707,8 @@
     "jsbn": {
       "version": "0.1.1",
       "resolved": "https://registry.npmjs.org/jsbn/-/jsbn-0.1.1.tgz",
-      "integrity": "sha1-peZUwuWi3rXyAdls77yoDA7y9RM="
+      "integrity": "sha1-peZUwuWi3rXyAdls77yoDA7y9RM=",
+      "optional": true
     },
     "json-parse-better-errors": {
       "version": "1.0.2",
@@ -1343,7 +1348,8 @@
     "safer-buffer": {
       "version": "2.1.2",
       "resolved": "https://registry.npmjs.org/safer-buffer/-/safer-buffer-2.1.2.tgz",
-      "integrity": "sha512-YZo3K82SD7Riyi0E1EQPojLz7kpepnSQI9IyPbHHg1XXXevb5dJI7tpyN2ADxGcQbHG7vcyRHk0cbwqcQriUtg=="
+      "integrity": "sha512-YZo3K82SD7Riyi0E1EQPojLz7kpepnSQI9IyPbHHg1XXXevb5dJI7tpyN2ADxGcQbHG7vcyRHk0cbwqcQriUtg==",
+      "optional": true
     },
     "semver": {
       "version": "5.7.1",
@@ -1532,7 +1538,8 @@
     "tweetnacl": {
       "version": "0.14.5",
       "resolved": "https://registry.npmjs.org/tweetnacl/-/tweetnacl-0.14.5.tgz",
-      "integrity": "sha1-WuaBd/GS1EViadEIr6k/+HQ/T2Q="
+      "integrity": "sha1-WuaBd/GS1EViadEIr6k/+HQ/T2Q=",
+      "optional": true
     },
     "typedarray": {
       "version": "0.0.6",
@@ -1632,9 +1639,9 @@
       }
     },
     "y18n": {
-      "version": "4.0.0",
-      "resolved": "https://registry.npmjs.org/y18n/-/y18n-4.0.0.tgz",
-      "integrity": "sha512-r9S/ZyXu/Xu9q1tYlpsLIsa3EeLXXk0VwlxqTcFRfg9EhMW+17kbt9G0NrgCmhGb5vT2hyhJZLfDGx+7+5Uj/w=="
+      "version": "4.0.1",
+      "resolved": "https://registry.npmjs.org/y18n/-/y18n-4.0.1.tgz",
+      "integrity": "sha512-wNcy4NvjMYL8gogWWYAO7ZFWFfHcbdbE57tZO8e4cbpj8tfUcwrwqSl3ad8HxpYWCdXcJUCeKKZS62Av1affwQ=="
     },
     "yargs": {
       "version": "14.2.3",