Happy to discuss whether this is a good idea or not, but right now
there is no way to update repositories so often you are left with
an empty first screen.
This doesn't worry about state management (e.g. remembering
whether we are refreshing or not and showing this when we resume the
activity). Instead, it listens for the refresh listener, and when
triggered it will set the refreshing state to not refreshing. For now
the notification can act as the feedback that something is happening.
34e176539b