This is the first version of graphql-relay-py that is compatible with graphql-core version 3.

Changes:

• Various changes to make this compatible with graphql-core version 3.
• Version 3 of graphql-core and graphql-relay-py require Python 3.6, 3.7 and 3.8.
• Support pyproject.toml and poetry.
• The utils module is now a package.