Changelog

Based on this issue #21, improved the following:

• Simplify Fields definition (rename graphene.{type}Field to graphene.{type}).
• Add Types dynamic instantiation into ObjectTypes, Interfaces (as field), or in Field kwargs (as Arguments)
• Add .List , .NonNull to Types
• Add Union Type
• Add Scalar Type (for having, for example a DateTime Scalar type)
• Improved tests and coverage
• Use graphql-django-view for the GraphQL Django view.