0.2.0

Added

• ExtractVersion class to extract the version line from a changelog file and to parse the semver content from a version line, see #4
• semver_line_regex and version_line_regex args for changelog2version to provide custom regular expressions to parse a version line from a changelog and to extract the semver content from a line

Changed

• Main parsing code of update_version script moved to new ExtractVersion class
• Extend usage example in README file
• Rename test data changelog files
• Split unittest for ExtractVersion from update_version test
• Let the pipeline fail is there are flake8 violations