* Run rubocop --autocorrect on app/, config/ and lib/, also manually fix some remaining style issues
* Run rubocop --autocorrect-all on db/
* Run rubocop --autocorrect-all on `spec/` and fix remaining issues
If a flavour has only one skin, the skin selector will be omitted. This
omits the user[setting_skin] field, and because that's the only
user[...] field on the page, the entire user object will not be present
in the request handler's params object.
This commit accounts for that scenario by avoiding params.require(:user)
and instead picking out what we need from the params hash.