DLTP-265 Add affiliation to works

Adding affilation list  as a enumerator and include name and label as i8n
Include affiliation as qualified DC and populate in all repository models
Include affilation metadata to all works and populate form field
adding helper method for affiliation and removing incorrect spec
Adding spec for affiliation
Include affiliation as part new work type
Fixed failing spec
Refactoring affilations as plain Ruby object
Merge pull request #72 from ndlib/DLTP-265

DLTP-265 Add affiliation to works