- Add basic pyproject.toml with build-system information
- Drop versioneer in favor of versioningit
- Delete versioneer install module and remove its setup.cfg config
- Replace `src/streamlink/_version.py` and load streamlink's version
string via versioningit. The module's `__version__` export will get
replaced by a static string on build-time when creating sdists/wheels,
which results in the old versioneer behavior with support for
editable installs.
- Make versioningit use the same version format as versioneer
- Update MANIFEST.in and .coveragerc
* build: use versioneer to set the build number
* build: update the deploy scripts to use versioneer
* release: update docs version and fix tarball version
* build: no need to install versioneer on travis, etc.