Graphene v3 compatibility

[fhennig]

Graphene v3 is still in beta, but pretty stable now (https://github.com/graphql-python/graphene/wiki/v3-release-notes#graphene-schema-no-longer-subclasses-graphqlschema-type), it would be great if graphene-mongo could be made compatible.

Only the graphene package has to be updated. I ran the tests in the repo locally with graphene v3.0b5 and 27/91 tests failed.

[byoung213]

Added in #172

[wowkin2]

@abawchen @arunsureshkumar can newer version (0.2.14 or 0.3.0) with upgrade to Graphene v3 come any time soon?
Graphene library is waiting just for this version to be released here:
graphql-python/graphene#1127

[Lwackp]

@arunsureshkumar why was the graphene dependency pinned to beta release3.0b7 in #172 ? Graphene 3.0.0 was released on Nov 13, 2021

[Lwackp]

I've created #186 to address this

[abhinand-c]

@arunsureshkumar This issue has been resolved, we can safely close it.