chore(package): update babel-core to version 6.23.0 (#3509)

https://greenkeeper.io/

Author: greenkeeperio-bot

package.json

@@ -44,8 +44,9 @@
     "ws": "2.0.3"
   },
   "devDependencies": {
+
     "babel-cli": "6.23.0",
-    "babel-core": "6.22.1",
+    "babel-core": "6.23.0",
     "babel-eslint": "^7.1.1",
     "babel-plugin-syntax-flow": "6.13.0",
     "babel-plugin-transform-flow-strip-types": "6.22.0",