add babel runtime to dev deps

Author: yyx990803

package.json

@@ -57,6 +57,7 @@
     "babel-core": "^6.8.0",
     "babel-loader": "^6.2.4",
     "babel-plugin-transform-runtime": "^6.8.0",
+    "babel-runtime": "^6.0.0",
     "babel-preset-es2015": "^6.6.0",
     "chai": "^3.0.0",
     "coffee-loader": "^0.7.2",