Ariadne

- Updated `graphql-core-next` to `graphql-core` 3.

- Added recursive loading of GraphQL schema files from provided path.
- Added support for passing multiple bindables as `*args` to `make_executable_schema`.
- Updated Starlette dependency to 0.13.
- Made `python-multipart` optional dependency for `asgi-file-uploads`.
- Added Python 3.8 to officially supported versions.

- Added support for custom schema directives.
- Added support for synchronous extensions and synchronous versions of `ApolloTracing` and `OpenTracing` extensions.
- Added `context` argument to `has_errors` and `format` hooks.

- Updated `graphql-core-next` to 1.1.1 which has feature parity with GraphQL.js 14.4.0.
- Added basic extensions system to the `ariadne.graphql.graphql`. Currently only available in the `ariadne.asgi.GraphQL` app.
- Added `convert_kwargs_to_snake_case` utility decorator that recursively converts the case of arguments passed to resolver from `camelCase` to `snake_case`.
- Removed `default_resolver` and replaced its uses in library with `graphql.default_field_resolver`.
- Resolver returned by `resolve_to` util follows `graphql.default_field_resolver` behaviour and supports resolving to callables.
- Added `is_default_resolver` utility for checking if resolver function is `graphql.default_field_resolver`, resolver created with `resolve_to` or `alias`.
- Added `ariadne.contrib.tracing` package with `ApolloTracingExtension` and `OpenTracingExtension` GraphQL extensions for adding Apollo tracing and OpenTracing monitoring to the API (ASGI only).
- Updated ASGI app disconnection handler to also check client connection state.
- Fixed ASGI app `context_value` option support for async callables.
- Updated `middleware` option implementation in ASGI and WSGI apps to accept list of middleware functions or callable returning those.
- Moved error formatting utils (`get_formatted_error_context`, `get_formatted_error_traceback`, `unwrap_graphql_error`) to public API.

- Added support for file uploads.

- Updated `graphql-core-next` to 1.0.4 which has feature parity with GraphQL.js 14.3.1 and better type annotations.
- `ariadne.asgi.GraphQL` is now an ASGI3 application. ASGI3 is now handled by all ASGI servers.
- `ObjectType.field` and `SubscriptionType.source` decorators now raise ValueError when used without name argument (eg. `foo.field`).
- `ScalarType` will now use default literal parser that unpacks `ast.value` and calls value parser if scalar has value parser set.
- Updated ``ariadne.asgi.GraphQL`` and ``ariadne.wsgi.GraphQL`` to support callables for ``context_value`` and ``root_value`` options.
- Added ``logger`` option to ``ariadne.asgi.GraphQL``, ``ariadne.wsgi.GraphQL`` and ``ariadne.graphql.*`` utils.
- Added default logger that logs to ``ariadne``.
- Added support for `extend type` in schema definitions.
- Removed unused `format_errors` utility function and renamed `ariadne.format_errors` module to `ariadne.format_error`.
- Removed explicit `typing` dependency.
- Added `ariadne.contrib.django` package that provides Django class-based view together with `Date` and `Datetime` scalars.
- Fixed default ENUM values not being set.
- Updated project setup so mypy ran in projects with Ariadne dependency run type checks against it's annotations.
- Updated Starlette to 0.12.0.