chore(package): update html-webpack-plugin to version 3.0.8

Closes #46

Author: greenkeeper[bot]

package.json

@@ -56,7 +56,7 @@
     "eslint-config-xo-react": "^0.11.0",
     "eslint-plugin-react": "^6.9.0",
     "file-loader": "^0.11.0",
-    "html-webpack-plugin": "^2.26.0",
+    "html-webpack-plugin": "^3.0.8",
     "postcss-cssnext": "^2.7.0",
     "postcss-loader": "^1.2.2",
     "regenerator": "^0.10.0",