* 🔧 Add pre-commit config
Similar to graphene and graphene-sqlalchemy
* ⬆ Bump black
* 👷 Lint on CI
* ⬆ Bump flake8-black
* 🔧 Keep excluding migrations
* ⬆ Bump flake8
* 🔧 Remove black and flake8 from tox config
* ⬆ Update pre-commit versions
* Upgrade syntax to python 3.7+
* Format with pre-commit
dedent docs/schema.py to allow formatting
* Fix tests on python 3.7
* 👽 Use .formatted instead of format_error
* ✅ Fix test with newer graphene
null default values (graphql-python/graphene@03277a5)
no more trailing newlines
* merge master into v3
* fix order_by snake casing by checking if value is None, switch executor to execution_context_class since schema.execute no longer supports executor
* fix linting by removing duplicate defintion and test of convert_form_field_to_string_list
