Create new schema for related update
Add tests for related actions
Merge branch '504-related-update-schema' of github.com:okfn/ckan into 504-related-update-schema
[#504] PEP8, and verify that items in original
related_item dict are still present after the
partial update.
Merge remote-tracking branch 'origin/master' into 504-related-update-schema
Merge pull request #1285 from okfn/504-related-update-schema

Create new schema for related update