build: Simplify babel build (graphql#493)

package.json

@@ -36,11 +36,8 @@
     "mocha": "--require resources/mocha-bootload src/**/__tests__/**/*.js"
   },
   "babel": {
-    "presets": [
-      "es2015"
-    ],
     "plugins": [
-      "transform-class-properties",
+      "transform-es2015-modules-commonjs",
       "transform-flow-strip-types"
     ]
   },
@@ -68,13 +65,9 @@
   "devDependencies": {
     "babel-cli": "6.26.0",
     "babel-eslint": "10.0.1",
-    "babel-plugin-transform-async-to-generator": "6.24.1",
-    "babel-plugin-transform-class-properties": "6.24.1",
+    "babel-plugin-transform-es2015-modules-commonjs": "^6.26.2",
     "babel-plugin-transform-flow-strip-types": "6.22.0",
-    "babel-plugin-transform-runtime": "6.23.0",
-    "babel-preset-es2015": "6.24.1",
     "babel-register": "6.26.0",
-    "babel-runtime": "6.26.0",
     "body-parser": "1.19.0",
     "chai": "4.2.0",
     "connect": "3.6.6",

resources/mocha-bootload.js

@@ -6,8 +6,4 @@
  *  LICENSE file in the root directory of this source tree. An additional grant
  *  of patent rights can be found in the PATENTS file in the same directory.
  */
-/* eslint-disable no-console */
-
-require('babel-register')({
-  plugins: ['transform-async-to-generator', 'transform-runtime'],
-});
+require('babel-register')();