There is an instantiation of Lock class inside Election class. This makes Election class dependent on Lock class. You can see instantiation at https://github.com/metaparticle-io/sync/blob/master/python/metaparticle_sync/election.py#L8:21.
IMHO, instance of Lock class should be supplied from outside. It removes dependency of Election class on Lock class. Also I believe it makes Election class more unit test friendly.
Let me know your thoughts. If you agree, I can send a PR.