`lastBuild` is a synchronous relationship on a branch model, so we need to
have a build record present when we put a default branch from a repository
model into the store. We don't send lastBuild's payload in pusher, so
we need to get it using an ajax call, if it's not already in the store.
In the future we may decide to make the relationship async, but I don't
want to change the code at the moment
Removed code was checking if we should handle a pusher event, ie. if the
event is associated with the user, or if we already have a record
associated with the event. We don't need the check now, because we no
longer use the common channel.
This commit just fixes things to the point where pusher updates are
applied to the store properly. This still lacks a business logic fixes,
so for example we won't update lastBuild's field, because there's no
such information from pusher.
One thing that is not standard here is a serializer for branch, which
uses @href as id. At this point branches don't have ids and ember-data
needs one, so using @href is the easiest way.
We sometimes miss pusher updates, which started to be more common
lately. Until we investigate what's going on, this should be a good
workaround for keeping UI in sync with the DB.
