Merge pull request #377 from no-reply/af7-rdf

Overhauling implementatation of ActiveFedora::Rdf
Move all the RDF related classes to the rdf directory
Merge pull request #378 from projecthydra/autoload_under

Move all the RDF related classes to the rdf directory
Removed deprecated YAMLAdapter
Merge pull request #379 from projecthydra/remove_yaml_adapter

Removed deprecated YAMLAdapter
Merging at @jcoyne request. Travis tests check out, so we should be good to go.
Bump version to 7.0.0.rc3
Merge pull request #12 from terrellt/oregon-af7

Added the ability to define a language on get_values.
Merge branch 'master' into oregon-af7
Fixed API on Identifiable#from_uri.