The fw-bot testing API should improve the perfs of mergebot tests
somewhat (less waiting around for instance).
The code has been updated to the bare minimum (context-managing repos,
change to PRs and replacing rolenames by explicit token provisions)
but extra facilities were used to avoid changing *everything*
e.g. make_commit (singular), automatic generation of PR refs, ...
The tests should eventually be updated to remove these.
Also remove the local fake / mock. Being so much faster is a huge
draw, but I don't really want to spend more time updating it,
especially when fwbot doesn't get to take advantage. A local /
lightweight fake github (as an external service over http) might
eventually be a good idea though, and more applicable (including to
third-parties).
Converge the pytest setups of runbot_merge and forwardport a bit
more (the goal is obviously to eventually share the infrastructure so
they run the same way).
Running multiple ngrok concurrently is only allowed from pro and up
(OOTB and without shenanigans) is only allowed from Pro and up. However
multiple tunnels through a single ngrok is allowed
-> when tunneling through ngrok, start the process without any tunnel,
use the API to create then remove the local tunnel, and shut down ngrok
IIF there's no tunnel left.
There's plenty of race conditions but given how slow tests are when they
involve github that's probably not an issue.
* extract method to create a PR object from a github result (from the
PR endpoint)
* move some of the remote's fixtures to a global conftest (so they can
be reused in the forwardbot)
