started Fries Museum
added fields (todo test)
fix fries museum
fries museum: production place singleton
docs: fix centraal museum utrecht, add friesmuseum
friesmuseum: static xml and image host
Merge branch 'friesmuseum' of https://github.com/bennokr/open-cultuur-data into bennokr-friesmuseum

Conflicts:
	ocd_backend/sources.json
Created sepearte extractor to extract static files
Some PEP8 related changes
Merge branch 'bennokr-friesmuseum'
Merge branch 'master' of https://github.com/openstate/open-cultuur-data