FEATURE: Serialized SSH Tunnel

[shyamd]

The SSH tunnel feature in MongoStore is really nice in python terminal or jupyter-notebook. Ideally, we could serialize the connection and have MongoStore initialize it when deserialized.

[mkhorton]

Seconded, this would be really useful. I've had builds break because of a flaky VPN.

[mkhorton]

Adding this to the docs would be appreciated too.

Alternatively, instead of making it serialized, an option on mrun e.g. mrun --ssh dtn where dtn is a host defined in your ~/.ssh/config might be all that's needed.

[shyamd]

Implemented in #320