Static and templates not installed during pip install

[dperetti]

Static and templates folders were not installed during pip install. As a consequence, widget in admin is broken.
Looks like a setup.py issue.

[seroy]

Oops, seems like @unaizalakain already made solution... Stupid situation) so i added some more features in #22:

• requirement django-postgres-extra upgraded to 1.11
• tests excluded from package installation