Prevent duplicate artists from being created; fix format issue on sync page
Add last_synched timestamp field to artist
Add last_synched timestamp field to artist
Revert "Add last_synched timestamp field to artist"

This reverts commit 18c570a59d48bf10bfb035b00974a514872028fb.
Revert "Revert "Add last_synched timestamp field to artist""

This reverts commit 1b1f393ff19dddfa56d41ba9237695f5cd9c1494.