added a display name field to entity
wrote a test for verifying that the unicode representation is mirrored in the display_name
wrote test for custom display name function
updated docs
updated travis db settings
removed lingering code
removed more lingering code
changed the unicode method for entities and removed more lingering code
tested the new unicode method.
removed unused field in select_related
Merge pull request #42 from wesleykendall/feature/optimize

Display names for entities