Update babel monorepo to v7.8.0

Author: renovate-bot

package.json

@@ -33,12 +33,12 @@
   },
   "dependencies": {},
   "devDependencies": {
-    "@babel/cli": "7.7.7",
-    "@babel/core": "7.7.7",
-    "@babel/plugin-proposal-async-generator-functions": "7.7.4",
-    "@babel/polyfill": "7.7.0",
-    "@babel/preset-env": "7.7.7",
-    "@babel/register": "7.7.7",
+    "@babel/cli": "7.8.0",
+    "@babel/core": "7.8.0",
+    "@babel/plugin-proposal-async-generator-functions": "7.8.0",
+    "@babel/polyfill": "7.8.0",
+    "@babel/preset-env": "7.8.0",
+    "@babel/register": "7.8.0",
     "ava": "2.4.0",
     "coveralls": "3.0.9",
     "esdoc": "1.1.0",