Gunicorn does not allow passing in a list of environment variables

[derektamsen]

The gunicorn module does not allow passing in a list of environment variables. It would be great to pass in an array or hash with custom environment variables that the gunicorn user will run with. This can allow some python apps to be configured without settings files or allow custom settings files to be passed in.

Ex. https://github.com/puppet-community/puppetboard#settings will read the os.env var PUPPETBOARD_SETTINGS=/some/file/path/settings.py to allow setting an alternait settings file. This allows for customization of the puppetboard service with out editing the built in settings file or managing a settings.py file in the directory where pip installed puppetboard.