Move profiles to users controller, add minotar support

* Created users_controller
* Profiles are now using the show action of the users controller
* Users are still using friendly URLs with username (e.g. `/users/John Doe`)
* Added support for [minotar](https://minotar.net) avatars
* No need for `profile_path(name)` because `user_path(user)` is generated automatically

minotar is not yet enabled because it needs an IGN which has yet to be added to users by migration.

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*Please note: This PR also contains #7 - that wasn't intended, sorry. Will remove if required*