Restructure resources and fix routes
Implement specific image show
Add group membership and image liking/disliking

Users can be in groups

Users can like or dislike specific images

Refactor view templates by using partials and rendering redundant code
to them

Refactor controller and models so that the controller does less and
relies on the methods the models provide

Connect groups and users through table group_membership
Add like counter
Add image tagging
Filter by tags
Searchable tags, mass asign tags to a single image