Add specs created by rspec-rails when regenerating scaffolds

Note that this adds specs for all possible controller actions, since
there isn't an easy way to limit which actions are generated in a
scaffold. Many of these will need to be removed or updated later.
Remove some CRUD actions from controller specs
Merge branch 'dev' into spec
Album routing
Merge branch 'dev' into spec
Artists routing
Better Artist route specs
Better Albums route specs
Genres routing specs
Tracks routes specs
Import route spec
Clean helper specs
Artist controller specs
Albums controllers specs
Tracks controller specs
Fixing Artists routes tests
Merge branch 'spec' into dev