Don't run amon as root during installation

[bascht]

(I hope it's okay if I grab issue #1 ;-) Congrats to open sourcing Amon! Very much looking forward to it!)

The install docs aren't totally clear which user the installation should be run as. I suggest switching to the amon user right after chowning the folders.

Otherwise this command

# To test if Amon is configured properly
python manage.py runserver

will create files as root in /opt/amon and the regular systemd installation won't come up. :)

[martinrusev]

@bascht Yep. Running with su - amon -c "python manage.py runserver" or something similar will be a much better solution