Good point, in general I simply disable queue jobs site setting in dev and avoid running sidekiq but you are right should be added, so I went ahead and added both 
Also, to clean up usage I added a symlink to bin/docker called d
So:
d/mailcatcher
d/sidekiq
d/bundle install
... and so on work ..
https://github.com/discourse/discourse/commit/97e2a614c8587bbd9535ed28dc1bcf766751b2cc