Change news edition to article

for #9
Change article rendering app to www
Merge branch 'article-editions' of git://github.com/theodi/odi_content_models

Conflicts:
	app/decorators/models/artefact_decorator.rb
	lib/odi_content_models/test_helpers/factories.rb
Merge pull request #12 from theodi/article-editions

Change news edition to article