Graph-wrap

type argument 1 must be str, not unicode

Various bug fixes and minor improvements.

**Full Changelog**: https://github.com/PaulGilmartin/graph_wrap/compare/0.1.1...0.1.2

Bux fix for https://github.com/PaulGilmartin/graph_wrap/issues?q=is%3Aissue+is%3Aclosed
Fixed tastypie docs

Ensure Decimal field can support both str and unicode

Fix setup.py dependencies

* Upgraded graphene-django dependency
* Fixed bug which occurred when 'type' was supplied with a unicode, not str.
* Added additional unit tests.