`post-receive` is only run on changes

[cloudhead]

Though this is expected git behavior, it creates a problem when the pre-receive hook succeeds but the post-receive hook fails. The next time we push, the post-receive hook isn't retried. This is only in cases where the hook has a bug that is later fixed, but this can happen.

Though we could fix this by having a commnand run the script, it's probably best to wait for replication-v3 to be merged.