feat: drop node < 6.5 (#216)

BREAKING CHANGE: requires node >= 6.5

config/build/babelrc.js

@@ -3,7 +3,6 @@ import presetReact from 'babel-preset-react';
 import preset2016 from 'babel-preset-es2016';
 import preset2017 from 'babel-preset-es2017';
 import presetStage1 from 'babel-preset-stage-1';
-import pluginNode6FunctionName from 'babel-plugin-transform-es2015-function-name';
 import pluginReactRequire from 'babel-plugin-react-require';
 import pluginTransformRuntime from 'babel-plugin-transform-runtime';
 import pluginTransformExportDefaultName from 'babel-plugin-transform-export-default-name-forked';
@@ -23,8 +22,6 @@ export default env => ({
         presetStage1,
     ].filter(Boolean),
     plugins: [
-        // The only missing plugin for node 6
-        env === 'server' && pluginNode6FunctionName,
         // Make optional the explicit import of React in JSX files
         pluginReactRequire,
         // Add Object.entries, Object.values and other ES2017 functionalities

package.json

@@ -47,7 +47,6 @@
     "babel-plugin-minify-guarded-expressions": "0.0.4",
     "babel-plugin-minify-replace": "0.0.3",
     "babel-plugin-react-require": "^3.0.0",
-    "babel-plugin-transform-es2015-function-name": "^6.22.0",
     "babel-plugin-transform-export-default-name-forked": "^1.2.2",
     "babel-plugin-transform-node-env-inline": "^6.8.0",
     "babel-plugin-transform-runtime": "^6.22.0",
@@ -98,6 +97,6 @@
     "webpack-hot-middleware": "^2.16.1"
   },
   "engines": {
-    "node": ">=6.0.0"
+    "node": ">=6.5.0"
   }
 }