There are few unrelated changes in this commit that I wasn't able to
split out, mostly due to laziness, so I'll list them here:
* The node startup logic is moved out of the main function, and into a
dedicated functionin `client.rs`.
* There is a tentative worker implementation that is untested, and
handles git replication both ways. It's likely lacking in various ways
but I wanted to get it in there anyway.
* `Address` was moved from `radicle-node` to `radicle`, because it's
needed to send `Connect` commands from the node handle.
* The `netservices` dependency was updated.
* Finally, there is a first end-to-end node test, which currently
doesn't use NoiseXK, but uses the new reactor in `netservices`.
Signed-off-by: Alexis Sellier <self@cloudhead.io>