Release version 2.2.0

[jnak]

Changelog

• Improve creation of column and sort enums (db3e9f4)

[jnak]

@Cito This is releasing your enum PR. This will make it easier for people to follow the enum example

[coveralls]

Coverage remained the same at 93.988% when pulling ca7be29 on jnak:rel-2.2.0 into 9594587 on graphql-python:master.

[Cito]

@jnak - I think we should also change the requirements.txt file like I sugested in #216. Since the ReadMe in the example directory recommends cloning from GitHub, we should install the currently cloned version instead of the version released on PyPI in order to make sure they always fit together. Also the current requirements.txt file has a version restriction for SQLAlchemy that is incompatible with the current restriction in our setup.py, so it needs to be fixed anyway.

[jnak]

@Cito Now that #218 is merged, can you also accept this one so people can start using your change? Some issues were opened that might be not be happening with your changes (ex #219).