Update gulp to the latest version 🚀 (#798)

* chore(package): update gulp to version 4.0.1

* chore(package): update lockfile package-lock.json

Author: greenkeeper[bot]

package-lock.json

@@ -54,7 +54,7 @@
     "eslint": "5.16.0",
     "eslint-plugin-flowtype": "3.5.1",
     "express": "4.16.4",
-    "gulp": "4.0.0",
+    "gulp": "4.0.1",
     "gulp-babel": "8.0.0",
     "gulp-derequire": "2.1.0",
     "gulp-insert": "0.5.0",