chore: dependencies update

- chore: update `@babel/plugin-external-helpers` to `7.0.0`
- chore: update `autoprefixer` to `9.3.1`
- chore: update `postcss-cli` to `6.0.1`
- chore: update `stylelint-scss` to `3.3.2`

Author: xidedix

package.json

@@ -77,16 +77,15 @@
   "devDependencies": {
     "@babel/cli": "^7.1.2",
     "@babel/core": "^7.1.2",
+    "@babel/plugin-external-helpers": "^7.0.0",
     "@babel/plugin-proposal-object-rest-spread": "^7.0.0",
     "@babel/plugin-proposal-throw-expressions": "^7.0.0",
     "@babel/plugin-transform-runtime": "^7.1.0",
     "@babel/preset-env": "^7.1.0",
-    "autoprefixer": "^9.2.1",
+    "autoprefixer": "^9.3.1",
     "babel-eslint": "^10.0.1",
-    "babel-plugin-external-helpers": "^7.0.0-beta.3",
     "babel-plugin-istanbul": "^5.1.0",
     "babel-plugin-transform-es2015-modules-strip": "^0.1.1",
-    "babel-plugin-transform-object-rest-spread": "^7.0.0-beta.3",
     "clean-css-cli": "^4.2.1",
     "copyfiles": "^2.1.0",
     "cross-env": "^5.2.0",
@@ -95,7 +94,7 @@
     "node-sass": "^4.9.4",
     "nodemon": "^1.18.4",
     "npm-run-all": "^4.1.3",
-    "postcss-cli": "^6.0.0",
+    "postcss-cli": "^6.0.1",
     "rimraf": "^2.6.2",
     "rollup": "^0.66.6",
     "rollup-plugin-babel": "^4.0.3",
@@ -107,7 +106,7 @@
     "stylelint-config-recommended-scss": "^3.2.0",
     "stylelint-config-standard": "^18.2.0",
     "stylelint-order": "^1.0.0",
-    "stylelint-scss": "^3.3.1",
+    "stylelint-scss": "^3.3.2",
     "uglify-js": "^3.4.9"
   },
   "peerDependencies": {