Updated the test federate ticking approach. Previously we'd had to
include a hard sleep to allow time for messages to come in due to a bug
in the Portico tick/callback processing. That bug has been fixed now.
Note that I haven't checked in the updated Portico library yet as there
is still some experimentation going on and so it's full of useless,
non-permanent logging. Will update this shortly, but need to get on and
fix the next test federate issue now.