add *.log and test.py
Remove use of timestamped value.

Thought it was dumb/inelegant to have a Value() object floating around
with value and timestamp .  Instead, now all messages are sent around
as json dicts.

The request enters the system as json, flows through to an endpoint
where it becomes a reply message, then flows back to the client.
No changes.

Deleted a few empty lines.
Finish put test on single local server
Add replies to put, get, delete.

Requests now flow into the system as json dicts and pass through until
it reaches an endpoint, the PersistenceStage being one of them.

It now returns a reply dict to be processed by the
InternalRequestCoordinator.
Add skeleton methods for failures.

Decided that MembershipStage should handle the announced/unannounced
failures since it’s in charge of detecting failures as well as the
consistent hash ring.
Add some logging and docstrings