Merge commit 'dc09c10fa8cc9230bf14e48d790c8f0c26043f8f' into glitch-soc/merge-upstream

Conflicts:
- `.rubocop_todo.yml`:
  Upstream re-generated the file, while glitch-soc has a specific ignore
  for some file.
  Updated the file as upstream did and kept our extra ignore.
- `config/webpack/shared.js`:
  Upstream added a plugin, but our files are pretty different.
  Added the plugin as well.
- `spec/helpers/application_helper_spec.rb`:
  Upstream refactored tests, but part of them were different because
  of glitch-soc's theming system.
  Applied the refactoring to glitch-soc's change.

package.json

@@ -60,6 +60,7 @@
     "babel-plugin-preval": "^5.1.0",
     "babel-plugin-transform-react-remove-prop-types": "^0.4.24",
     "blurhash": "^2.0.5",
+    "circular-dependency-plugin": "^5.2.2",
     "classnames": "^2.3.2",
     "cocoon-js-vanilla": "^1.3.0",
     "color-blend": "^4.0.0",