Update babel parser (#1114)

Author: vicapow

.babelrc

@@ -1,14 +1,14 @@
 {
   "presets": [
-    ["env", {
+    ["@babel/preset-env", {
       "targets": {
       "node": 6
       },
       "include": ["transform-regenerator"]
     }],
-    "flow"
+    "@babel/preset-flow"
   ],
-  "plugins": ["syntax-async-functions"],
+  "plugins": ["@babel/plugin-transform-async-to-generator"],
   "ignore": [
       "**/default_theme/assets/*"
   ]