Pytest-lambda

Added
- Add `py.typed` file to package to enable mypy static type checking
- Expose minimal generic typing on `LambdaFixture`

Fixed
- Avoid crash when running under PyCharm/pydev debugger due to `LambdaFixture.__class__` property

Changed
- Preserve declared order of arguments with `wrap_fixture` (decorated method's first, then wrapped fixture's, then `request`)
- DOC: add destructuring examples to README

BREAKING
- Due to destructured parametrization now being powered by a custom `pytest_generate_tests` hook, incompatibilities may have been introduced. Out of caution, the major version has been bumped.

Added
- Add support for destructuring referential tuple lambda fixtures (e.g. `x, y, z = lambda_fixture('a', 'b', 'c')`)
- Add support for destructuring parametrized lambda fixtures (e.g. `a, b, c = lambda_fixture(params=[pytest.param('ayy', 'bee', 'see')])`)

Added
- Add support for async/awaitable fixtures

Changed
- Add support for pytest versions 7.0 and 7.1
- Relax pytest version pin to allow all versions under 8.x

Fixed
- Avoid `ValueError: wrapper has not been initialized` when using implicit referential lambda fixtures (e.g. `name = lambda_fixture()`) in combination with `py.test --doctest-modules`