Adds login requirements.
Requires login to create artist, create gallery, and edit artist.
Requires login to create, edit, and delte a gallery.
Adds registrations tests and creation methods.
Subs in full name when artist doesn't have a display name on index and show pages.
Changes galleries show only display artwork for that gallery.
Adds features test for list of galleries.
Removes nesting of galleries under artists.
Saves thumbnails of images for loading in galleries.
Adds resizing for large images
Adds color palette to artwork edit page.
Fixes bug occurring when artists try to add artwork without selecting image.