Started using babel-preset-latest (#490)

* Started using babel-preset-latest

* Updated babel dependencies

* Remove redundant babel-plugin-syntax-async-functions

* Disabled redundant regenerator transform

config/babel.dev.js

@@ -14,24 +14,21 @@ module.exports = {
   // It enables caching results in OS temporary directory for faster rebuilds.
   cacheDirectory: true,
   presets: [
-    // let, const, destructuring, classes, modules
-    require.resolve('babel-preset-es2015'),
-    // exponentiation
-    require.resolve('babel-preset-es2016'),
+    // Latest stable ECMAScript features
+    require.resolve('babel-preset-latest'),
     // JSX, Flow
     require.resolve('babel-preset-react')
   ],
   plugins: [
-    // function x(a, b, c,) { }
-    require.resolve('babel-plugin-syntax-trailing-function-commas'),
-    // await fetch()
-    require.resolve('babel-plugin-syntax-async-functions'),
     // class { handleClick = () => { } }
     require.resolve('babel-plugin-transform-class-properties'),
     // { ...todo, completed: true }
     require.resolve('babel-plugin-transform-object-rest-spread'),
     // function* () { yield 42; yield 43; }
-    require.resolve('babel-plugin-transform-regenerator'),
+    [require.resolve('babel-plugin-transform-regenerator'), {
+      // Async functions are converted to generators by babel-preset-latest
+      async: false
+    }],
     // Polyfills the runtime needed for async/await and generators
     [require.resolve('babel-plugin-transform-runtime'), {
       helpers: false,

config/babel.prod.js

@@ -11,24 +11,21 @@ module.exports = {
   // Don't try to find .babelrc because we want to force this configuration.
   babelrc: false,
   presets: [
-    // let, const, destructuring, classes, modules
-    require.resolve('babel-preset-es2015'),
-    // exponentiation
-    require.resolve('babel-preset-es2016'),
+    // Latest stable ECMAScript features
+    require.resolve('babel-preset-latest'),
     // JSX, Flow
     require.resolve('babel-preset-react')
   ],
   plugins: [
-    // function x(a, b, c,) { }
-    require.resolve('babel-plugin-syntax-trailing-function-commas'),
-    // await fetch()
-    require.resolve('babel-plugin-syntax-async-functions'),
     // class { handleClick = () => { } }
     require.resolve('babel-plugin-transform-class-properties'),
     // { ...todo, completed: true }
     require.resolve('babel-plugin-transform-object-rest-spread'),
     // function* () { yield 42; yield 43; }
-    require.resolve('babel-plugin-transform-regenerator'),
+    [require.resolve('babel-plugin-transform-regenerator'), {
+      // Async functions are converted to generators by babel-preset-latest
+      async: false
+    }],
     // Polyfills the runtime needed for async/await and generators
     [require.resolve('babel-plugin-transform-runtime'), {
       helpers: false,

package.json

@@ -29,19 +29,16 @@
   },
   "dependencies": {
     "autoprefixer": "6.4.0",
-    "babel-core": "6.11.4",
+    "babel-core": "6.14.0",
     "babel-eslint": "6.1.2",
     "babel-jest": "14.1.0",
-    "babel-loader": "6.2.4",
-    "babel-plugin-syntax-async-functions": "6.8.0",
-    "babel-plugin-syntax-trailing-function-commas": "6.8.0",
+    "babel-loader": "6.2.5",
     "babel-plugin-transform-class-properties": "6.11.5",
     "babel-plugin-transform-object-rest-spread": "6.8.0",
     "babel-plugin-transform-react-constant-elements": "6.9.1",
-    "babel-plugin-transform-regenerator": "6.11.4",
+    "babel-plugin-transform-regenerator": "6.14.0",
     "babel-plugin-transform-runtime": "6.12.0",
-    "babel-preset-es2015": "6.9.0",
-    "babel-preset-es2016": "6.11.3",
+    "babel-preset-latest": "6.14.0",
     "babel-preset-react": "6.11.1",
     "babel-runtime": "6.11.6",
     "case-sensitive-paths-webpack-plugin": "1.1.3",