fix(package): update babel-preset-extplug to version 4.0.0 (#29)

Author: greenkeeper[bot]

package.json

@@ -17,7 +17,7 @@
   "dependencies": {
     "babel-core": "^6.26.0",
     "babel-loader": "^7.1.2",
-    "babel-preset-extplug": "^3.0.0",
+    "babel-preset-extplug": "^4.0.0",
     "chalk": "^2.2.0",
     "commander": "^2.11.0",
     "css-loader": "^0.28.7",