Don't panic if Timings are not provided in the Request

[jorendorff]

Also adds a test that actually binds the server to the network and tries to talk to it using the client.

This isn't as good as testing the example executables, but it was easy.

Fixes #5.

[patrickt]

This is the solution I landed on, too; I delayed in submitting a PR because I wanted to see if I could use get_mut() instead. I ran up against a wall so I think this is fine for now.