[POLISH] Add missing semicolon
[FEATURE] Artists: add Artists and ArtistReleases to backend
[FEATURE] Artists: add ability to create artists
[BUG] Add missing response object
[FEATURE] Artists: can delete an artist
[FEATURE] Artists: can show artists
[FEATURE] Artists: can update artists
[REFACTOR] Artists: create allToJSON method on Artist model
[FEATURE] Artists: add ability to create releases through artists
[FEATURE] Releases: clean up when destroying
[FEATURE] Artists: sideload releases
[BUG] Make sure models' toJSON methods clone values
[FEATURE] Artists: add ability to list releases
[FEATURE] Artists: list artists on releases
[FEATURE] Artists: sideload artists when updating release
[REFACTOR] Remove most references to 'sideloading'
[FEATURE] Artists: Make release Ember route
[FEATURE] Artists: add 'add-artist' template to release
[FEATURE] Artists: add client ability to add artists to release from list
[FEATURE] Artist: able to add existing artists to release