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New features:
- No longer test on Python 3.4, 3.5 and PyPy2, because we cannot get it to work.
Technically it should still work, it is just no longer tested.
Do not expect much development on branch 4.x anymore.
The main branch will be for the remaining Python versions that we support.
[maurits]
Bug fixes:
- Test with GitHub Actions. [maurits]