Graphene 0.10.0 - Middleware and multiple bux fixes

Changelog

Breaking:

• Removed the plugin functionality, replaced by with Middleware. #176

Bug fixes:

• Support with_context on ClientIDMutation.mutate_and_get_payload. 61e7bee
• Added interfaces field into a ObjectType 10304eb
• Allow string references in InputTypes d6740e9
• Fixed django OneToOne inverse relationship conversion b431bfe
• Allow numbers in to_constant ae8a23b
• Fix context arg in connections 8907449