Context

According to typing.python.org:

Package maintainers who wish to support type checking of their code MUST add a marker file named py.typed to their package supporting typing.

At the same time:

The single-file module should be refactored into a package and indicate that the package supports typing as described above.

Since the Allure API is exposed to users via the allure.py module (not via a package), it can't be affected by py.typed.

Solution

This PR refactors allure.py into a package. Now the allure-python-commons project defines two packages: allure_commons (for integrations) and allure (for test authors). Both packages include py.typed, which enables type checking.

Currently, this mainly affects type checking of functions with @allure.step applied to them (see #731).

More typing annotations will be added in the future.

Other changes

• standardize quotes in allure-python-commons/setup.py
• fix description type of allure-python-commons
• fix typing of allure.dynamic.parameter's mode

Fixes #731
Supersedes #848