Graphene>=3.0 Integration

[melvinkcx]

With graphene==3.0b1 being released, we can start looking into the integration with it.

For graphql-utilities to work with graphene>=3.0, we need to solve these issues:

• How to define cost in graphene, since schemas are defined using classes
• How to pass custom context value and ExecutionContext class for execution in graphene

[melvinkcx]

I started to integrate this lib with graphene but came across a roadblock. Defining fields with custom directive is not possible due to the lack of support in graphql-core. I created an issue here to gather the wisdom of the community.

After some conversation with the Graphene community on Slack, I realized there is an on-going discussion about supporting such feature.

So far there isn't a good workaround that doesn't require us to rewrite the logic in our CostAnalysisVisitor class yet