Merge pull request #201 from david-lev/dev

[version] bump version to 4.0.0 and update changelog for latest release

[version] new beta version 4.0.0b7

[version] new beta version 4.0.0b6

[version] new beta version 4.0.0b5

[changelog] fix typo

[version] new beta version 4.0.0b3

[version] new beta version 4.0.0b1

Merge pull request #176 from david-lev/dev

3.9.0

Merge pull request #168 from david-lev/dev

Template validation

Merge pull request #166 from david-lev/dev

[ci] remove condition to publish to PyPI only on tag pushes