Fix enum column conversion by "instantiating" Enum

[thejcannon]

Fixes #196 and #199.
See also graphql-python/graphene#932

[coveralls]

Coverage increased (+0.09%) to 91.989% when pulling d7f9085 on thejcannon:enums_support into c9af40c on graphql-python:master.

[coveralls]

Coverage increased (+0.09%) to 91.989% when pulling 53f107e on thejcannon:enums_support into c9af40c on graphql-python:master.

[jnak]

Looks good! I just had a couple of very minor comments.

[thejcannon]

Once this gets merged in, I wouldn't mind resolving the conflicts in #165 with my changes.
I'll post a new PR for that.

[jnak]

@thejcannon After commented on this PR, I caught up with this one #98. Do you expect your PR to conflict with that one as well?

[thejcannon]

Actually I looked at #165 for this issue and made this: thejcannon@737e288

So you could close both of those once that PR is made/merged.

[jnak]

#165 seems to duplicate most of the thing from #98. Since #98 was first and there has been quite a bit of conversation there, I'd rather merge this one over #165.

Would you mind taking a look at it and let me know what you think?

[Cito]

@jnak - #165 is pretty much like #98, but only part of it. It does not contain the name mangling, does not integrate the sort enums, and has fewer tests. It's a bit unfortunate that this stalled for so long that people created duplicate solutions and the code diverged.

[jnak]

Closing since #210 got merged