Update to the latest version of babel

Fixes #25

Author: dschafer

package.json

@@ -44,8 +44,8 @@
     "babel-runtime": "5.6.12"
   },
   "devDependencies": {
-    "babel": "5.6.12",
-    "babel-core": "5.6.12",
+    "babel": "5.6.14",
+    "babel-core": "5.6.20",
     "babel-eslint": "3.1.23",
     "chai": "3.0.0",
     "chai-as-promised": "5.1.0",