Adding worker state and celery supervisor configuration.
Rework how supervisor group is added so that it can be extending by the worker.
Add comment to top.sls about enabling celery worker.
Add docs on adding the Celery worker process via the Salt states.
Add note about supervisor processes failing on the initial provision.
Update configuration paths to include the environment.
Note that it should be possible to run multiple environments on the same machine.
Update states to use variables and macros for common path and file locations. Change gunicorn/nginx configurations to use a unix socket rather than port.
Merge pull request #41 from caktus/multiple-environments

Multiple Environments. Fixes #33.