Rebasehelper

Added
- Added tests for `SpecContent` class
- Enabled and configured [Packit-as-a-Service](https://packit.dev/packit-as-a-service/)

Fixed
- Added exception handling to PyPI release webhook endpoint
- Fixed `TestCLI.test_cli_unit()` test
- Updated `MANIFEST.in` to include all necessary files

Changed
- Improved tests for `Application` class
- `SpecFile.update_changelog()` now creates *%changelog* section if it doesn't exist
- **rebase-helper** now uses `setuptools-scm` to determine version from git
- `setup.py sdist` now supports overriding distribution base name with `--base-name` option

Fixed
- Fixed PyPI release webhook endpoint

Changed
- Removed direct dependencies preventing PyPI release

Added
- Added possibility for plugins to specify their own arguments
- Added basic type hints and enabled mypy linter
- Added *rust* package category
- **replace-old-version** SPEC hook can now replace old version with `%{version}` macro
- **replace-old-version** SPEC hook can now replace also parts of version in Sources and Patches

Fixed
- Fixed broken ansicolors dependency
- Fixed printing of output of unavaiable checkers
- Fixed determining unmatched quotation in *%prep* section
- Made **files** build log hook handle conditions and macros in *%files* section
- **files** build log hook now adds man pages in a way that follows [Fedora Packaging Guidelines](https://docs.fedoraproject.org/en-US/packaging-guidelines/#_manpages)
- **files** build log hook now ignores debuginfo files
- Fixed issues with polluted global macro namespace when parsing multiple different SPEC files
- Fixed handling of remote downstream patches (URLs)
- Fixed parsing of patch strip options in *%prep*
- Fixed wrapping of extra long lines in the usage documentation
- Sources from lookaside cache are now downloaded to a proper location

Changed
- Restructured the code layout of plugins
- Refactored parts of SpecFile class
- Disabled removing of "unused" patches
- `mock` is now automatically run with superuser privileges if necessary
- Local builder is now used if `--get-old-build-from-koji` is specified and the build can't be downloaded from Koji
- checkers (even the default ones) are now skipped if they are not available
- Sources are now copied to destination if they cannot be extracted
- Reimplemented downloading Koji builds
- Updated documentation

Removed
- Removed Python 2 support

Fixed
- Fixed handling of SPEC files with conditionalized sections
- Fixed **replace-old-version** SPEC hook not to update version in *%changelog* and local sources
- Fixed capturing RPM error output during SPEC parsing
- Fixed handling of absolute *%license* and *%doc* paths in **files** build log hook
- Fixed logging of SRPM and RPM build errors

Changed
- Updated packit configuration for packit 0.2.0
- Adapted to upcoming change in RPM python API
- Made `SpecFile` class more suitable for external use

Added
- Added support for [packit](https://github.com/packit-service/packit)
- Added SPEC hook for replacing old version string

Fixed
- Fixed documentation building by mocking `requests-gssapi`
- Fixed `TestOutputTool` for checkers

Changed
- Build log hooks are now run only if build of **new** binary packages fails
- It is now possible to use `--get-old-build-from-koji` option without FAS

Fixed
- Made `GitPatchTool` auto-skip empty commits caused by new rebase implementation in **git** 2.20
- Fixed `TestGitHelper` to work on real systems with existing git configuration