Use babel-preset-env.

Author: ben-eb

.babelrc

@@ -1,5 +1,9 @@
 {
-  "presets": ["es2015"],
+  "presets": [["env", {
+    "targets": {
+      "node": 4
+    }
+  }]],
   "plugins": ["add-module-exports"],
   "env": {
     "development": {

package.json

@@ -26,7 +26,7 @@
     "babel-core": "^6.21.0",
     "babel-eslint": "^7.1.1",
     "babel-plugin-add-module-exports": "^0.2.1",
-    "babel-preset-es2015": "^6.18.0",
+    "babel-preset-env": "^1.4.0",
     "babel-register": "^6.18.0",
     "cross-env": "^3.1.4",
     "del-cli": "^0.2.1",