chore(package): update babel-cli to version 6.11.4 (#2339)

https://greenkeeper.io/

Author: greenkeeperio-bot

package.json

@@ -49,7 +49,7 @@
     "ws": "1.1.1"
   },
   "devDependencies": {
-    "babel-cli": "6.8.0",
+    "babel-cli": "6.11.4",
     "babel-core": "6.10.4",
     "babel-plugin-syntax-flow": "6.8.0",
     "babel-plugin-transform-flow-strip-types": "6.8.0",