1.7.0

Added

• -f / --flynt option for converting old-style format strings to f-strings as supported in Python 3.6+.
• Make unit tests compatible with pytest --log-cli-level==DEBUG. Doctests are still incompatible due to
  pytest#5908 <https://github.com/pytest-dev/pytest/issues/5908>_.
• Black's target-version = configuration file option and -t / --target-version command line option
• In README.rst, link to GitHub searches which find public repositories that use Darker.
• Linters are now run twice: once for rev1 to get a baseline, and another time for rev2 to get the current situation. Old linter messages which fall on unmodified lines are hidden, so effectively the user gets new linter messages introduced by latest changes, as well as persistent linter messages on modified lines.
• --stdin-filename=PATH now allows reading contents of a single file from standard input. This also makes :STDIN:, a new magic value, the default rev2 for --revision.
• Add configuration for darglint and flake8-docstrings, preparing for enabling those linters in CI builds.

Fixed

• Compatibility of highlighting unit tests with Pygments 2.14.0.
• In the CI test workflow, don't use environment variables to add a Black version constraint to the pip command. This fixes the Windows builds.
• Pass Git errors to stderr correctly both in raw and encoded subprocess output mode.
• Add a work-around for cleaning up temporary directories. Needed for Python 3.7 on Windows.
• Split and join command lines using shlex from the Python standard library. This deals with quoting correctly.
• Configure coverage to use relative paths in the Darker repository. This enables use of cov_to_lint.py
• Satisfy Pylint's use-dict-literal check in Darker's code base.
• Use !r to quote values in format strings as suggested by recent Flake8 versions.