Remove unnecessary transform plugins for object spread to work (#1052)

* Update `babel-plugin-transform-object-rest-spread` to v6.19.0 The `babel-plugin-transform-object-rest-spread` v6.19.0 update will allow us to remove the `babel-plugin-transform-es2015-destructuring` and `babel-plugin-transform-es2015-parameters` as the object rest spread transform will now work standalone and not require additional tranforms * Remove unnecessary babel transform plugins from babel-preset-react-app The `babel-plugin-transform-object-rest-spread` v6.19.0 update makes these plugins unnecessary, as v6.19.0 can be used stand-alone

Author: valscion

packages/babel-preset-react-app/index.js

@@ -27,15 +27,7 @@ const plugins = [
  regenerator: true,
  // Resolve the Babel runtime relative to the config.
  moduleName: path.dirname(require.resolve('babel-runtime/package'))
- }],
- // The following two plugins are currently necessary to get
- // babel-preset-env to work with rest/spread. More info here:
- // https://github.com/babel/babel-preset-env#caveats
- // https://github.com/babel/babel/issues/4074
- // const { a, ...z } = obj;
- require.resolve('babel-plugin-transform-es2015-destructuring'),
- // const fn = ({ a, ...otherProps }) => otherProps;
- require.resolve('babel-plugin-transform-es2015-parameters')
+ }]
  ];
 
 // This is similar to how `env` works in Babel:

packages/babel-preset-react-app/package.json

@@ -12,9 +12,7 @@
  ],
  "dependencies": {
  "babel-plugin-transform-class-properties": "6.16.0",
- "babel-plugin-transform-es2015-destructuring": "6.16.0",
- "babel-plugin-transform-es2015-parameters": "6.17.0",
- "babel-plugin-transform-object-rest-spread": "6.16.0",
+ "babel-plugin-transform-object-rest-spread": "6.19.0",
  "babel-plugin-transform-react-constant-elements": "6.9.1",
  "babel-plugin-transform-react-jsx-self": "6.11.0",
  "babel-plugin-transform-react-jsx-source": "6.9.0",