Update babel-preset-env to latest

Author: binoculars

package.json

@@ -29,7 +29,7 @@
     "aws-sdk-on-lambda": "binoculars/aws-sdk-js-on-lambda",
     "azure-storage": "^2.1.0",
     "babel-cli": "^6.24.1",
-    "babel-preset-env": "^1.4.0",
+    "babel-preset-env": "^1.6.1",
     "chalk": "^2.0.1",
     "del": "^3.0.0",
     "google-cloud": "^0.55.0",