Add webpack-cli to other dummy webpack test folders

Author: BookOfGreg

test/dummy_webpacker1/package.json

@@ -29,6 +29,7 @@
     "sass-loader": "^6.0.5",
     "style-loader": "^0.17.0",
     "webpack": "^2.5.1",
+    "webpack-cli": "^3.3.6",
     "webpack-manifest-plugin": "^1.1.0",
     "webpack-merge": "^4.1.0"
   },