Display country field in Django Admin as an additional column in Project's list

[arturtamborski]

Every project has a country related to it, so it would be cool to see it right away in the list view, as an additional column. It should be also filterable.

[hkaczmarek90]

It's similar to my last commit - I can do that also.

[arturtamborski]

Done - this column now displays project (which underneath is a driver's country).
Thanks for your work.