fix: empty build due babel incorrect configuration (#341)

The PR #315 added @babel/core >= 7.*. upgrading/using babel v7
  requires, making certian changes, e.g using @babel...etc. This
  lead to `npm run build` being interrupted/exited.without
  generating the /dist folder.

  Luckily, there is a pacakge to automate migration of config
  using `npx babel-upgrade --write`, followed by `npm install`, and
  few minor changes, the dist folder came to life again.

  This shall fixes this openedx/wg-build-test-release#166. and
  probably making this openedx/edx-platform#30309 unnecessary.

  Note: This change adds "^7.0.0-bridge.0" as devDep, this is
  needed because we have pacakges that uses Babel 6, which are
  jest and babel-jest. once we upgrade to babel-jest and jest
  >=24.*.* the pacakge shall be removed.

.babelrc

@@ -1,23 +1,32 @@
 {
   "presets": [
-    ["env", {
-      "targets": {
-        "browsers": ["last 2 versions", "ie 11"]
+    [
+      "@babel/preset-env",
+      {
+        "targets": {
+          "browsers": [
+            "last 2 versions",
+            "ie 11"
+          ]
+        }
       }
-    }],
-    "babel-preset-react"
+    ],
+    "@babel/preset-react"
   ],
   "plugins": [
-    "transform-object-rest-spread",
-    "transform-class-properties"
+    "@babel/plugin-proposal-object-rest-spread",
+    "@babel/plugin-proposal-class-properties"
   ],
   "env": {
     "i18n": {
       "plugins": [
-        ["react-intl", {
-          "messagesDir": "./temp/babel-plugin-react-intl",
-          "enforceDescriptions": true
-        }]
+        [
+          "react-intl",
+          {
+            "messagesDir": "./temp/babel-plugin-react-intl",
+            "enforceDescriptions": true
+          }
+        ]
       ]
     }
   }