Merge branch 'upgrade-babel-deps' into 'master'

Upgrade babel to v7.2

See merge request gitlab-org/gitlab-ce!24259

.babelrc.js

@@ -18,6 +18,7 @@ const plugins = [
   '@babel/plugin-syntax-import-meta',
   '@babel/plugin-proposal-class-properties',
   '@babel/plugin-proposal-json-strings',
+  '@babel/plugin-proposal-private-methods',
 ];
 
 // add code coverage tooling if necessary

package.json

@@ -19,12 +19,13 @@
     "webpack-prod": "NODE_ENV=production webpack --config config/webpack.config.js"
   },
   "dependencies": {
-    "@babel/core": "^7.1.2",
-    "@babel/plugin-proposal-class-properties": "^7.1.0",
-    "@babel/plugin-proposal-json-strings": "^7.0.0",
-    "@babel/plugin-syntax-dynamic-import": "^7.0.0",
-    "@babel/plugin-syntax-import-meta": "^7.0.0",
-    "@babel/preset-env": "^7.1.0",
+    "@babel/core": "^7.2.2",
+    "@babel/plugin-proposal-class-properties": "^7.2.3",
+    "@babel/plugin-proposal-json-strings": "^7.2.0",
+    "@babel/plugin-proposal-private-methods": "^7.2.3",
+    "@babel/plugin-syntax-dynamic-import": "^7.2.0",
+    "@babel/plugin-syntax-import-meta": "^7.2.0",
+    "@babel/preset-env": "^7.2.3",
     "@gitlab/csslab": "^1.8.0",
     "@gitlab/svgs": "^1.47.0",
     "@gitlab/ui": "^1.20.0",