gulp from v4.0.0 tag, because 4.0 branch has been deleted

package.json

@@ -130,7 +130,6 @@
     "fast-levenshtein": "^2.0.6",
     "file-loader": "^1.1.11",
     "fuse.js": "^3.2.0",
-    "gulp": "github:gulpjs/gulp#4.0",
     "gulp-autoprefixer": "^5.0.0",
     "gulp-debug": "^3.2.0",
     "gulp-eslint": "^4.0.0",
@@ -254,7 +253,7 @@
     "geckodriver": "^1.12.2",
     "gh-pages": "^1.2.0",
     "gifencoder": "^1.1.0",
-    "gulp": "github:gulpjs/gulp#6d71a658c61edb3090221579d8f97dbe086ba2ed",
+    "gulp": "github:gulpjs/gulp#v4.0.0",
     "gulp-babel": "^7.0.0",
     "gulp-json-editor": "^2.2.1",
     "gulp-livereload": "^3.8.1",