Basic bootstrap setup
More bootstrap setup
Initial nav bar styling
Revert gallery styling
Make likes polymorphic

* Update likes table to include content_type and content_id
* Update models with polymorphic relationship
* Update routes for liking/unliking
* Create controller for image_likes
* Extract partial for displaying number of likes and like/unlike
* Update imges#show to use partial
Make galleries likable

* Add like relationship to Gallery
* Add liked_galleries to User
* Show like count and button on galleries#show
* Add routes for gallery likes
* Create gallery_likes_controller
* Refactor like methods in User to accept any likable object
Rename content to likeable for likes
Style image thumbnails as grids
Update Styles

* Style h1 headers on most pages
* Update styles for image tags
* Update styles for likes partial