Added Tobias to contributors.
Split test between setup/cleanup and submitter.
API commands now return the UUID as part of the response.

This allows to do `@api originate ...` and grab the call's UUID as `res.uuid`.
Report errors in `command_uuid` submission (Fixes #16)
Force `command_uuid` to at least map on the call's UUID (Fixes #17)

The main issue is still the same: FreeSwitch provides no way to uniquely track a command on the socket interface. It only replies `+OK` with no indication of what the `Application-UUID` will be. Monitoring `CHANNEL_EXECUTE` on a busy system doesn't help since those events might be submitted out-of-order.
Bump dependencies.
Corrected `command_uuid` to still support server-side (#16)
Corrected tests to account for load on the test machine.

The `cps` value can now be adjusted.