Add combined worker_plus_beat process

[ukch]

Limit celery, beat and web to 1 process each

This PR fixes issue #19

[MechanisM]

Not a good idea, it is better to just add additional uwsgi options "smart-attach-daemon" and put celery there. As example:
smart-attach-daemon = sentry --config=sentry.conf.py celery worker --loglevel=INFO
smart-attach-daemon = sentry --config=sentry.conf.py celery beat --loglevel=INFO

This way, Procfile will have just one "web:" and celery would be started by uwsgi.

[hadifarnoud]

@MechanisM can you please write the full procfile line?

[MechanisM]

Hey, @hadifarnoud! I think it should be smth like that
Procfile:
web: uwsgi --ini=uwsgi.ini --http=0.0.0.0:$PORT
just it, and remove the other lines.

In uwsgi.ini append at the end:

attach-daemon = sentry --config=sentry.conf.py run worker --loglevel=INFO
attach-daemon = sentry --config=sentry.conf.py run cron --loglevel=INFO
attach-daemon = sentry --config=sentry.conf.py upgrade --noinput

Not tested btw. Read the docs for uwsgi's attach-daemon