I bump the user_version to 3 at the same time. This table will be used
to hold listenbrainz listens that have not yet been submitted to the
listenbrainz server. I also give the Track table functions to get and
delete listens from this table as needed by the listenbrainz thread.
Signed-off-by: Anna Schumaker <Anna@NoWheyCreamery.com>
