* Attempt canceling sessions by the client
In some circumstances (like a Ctrl-C), the client knows it's shutting
down and the TOFU token will be lost. In this case it makes sense to
cancel the session rather than have it time out. This introduces a
command enum to the handshake message which can be used for the client
to send commands to the worker -- in this case the only specified
command is to cancel the session. It doesn't occur if the session is
already timed out or if we can't authorize connections as this generally
means the session is already invalid.
* Update deps
This also updates for the new (and required) paradigm for registering
service implementations as spelled out in
https://github.com/grpc/grpc-go/issues/3385
* Roll back dockertest
It's up to the worker to understand what a change in state means, so
there was no functional difference between simply sending a state change
request and a cancel request.
* Possible api changes.
* Worker API update.
* Updating import alias name.
* Moving session down a level as a member of the GetSessionResponse.
* Marshal the auth flag into the GetSessionResponse proto instead of the session.
Michael Gaffney
Jeff Mitchell
Jim
Todd Knight