chore(package): update babel-core to version 6.23.1 (#3512)

https://greenkeeper.io/

Author: greenkeeperio-bot

package.json

@@ -46,7 +46,7 @@
   "devDependencies": {
 
     "babel-cli": "6.23.0",
-    "babel-core": "6.23.0",
+    "babel-core": "6.23.1",
     "babel-eslint": "^7.1.1",
     "babel-plugin-syntax-flow": "6.13.0",
     "babel-plugin-transform-flow-strip-types": "6.22.0",