Version 1.3.0

Added

• Support for Black's --skip-magic-trailing-comma option
• darker --diff output is now identical to that of black --diff
• The -d / --stdout option outputs the reformatted contents of the single Python
  file provided on the command line.
• Terminate with an error if non-existing files or directories are passed on the command
  line. This also improves the error from misquoted parameters like "--lint pylint".
• Allow Git test case to run slower when checking file timestamps. CI can be slow.
• Fix compatibility with Black >= 21.7b1.dev9
• Show a simple one-line error instead of full traceback on some unexpected failures
• Skip reformatting files set to be excluded by Black in configuration files

Fixed

• Ensure a full revision range --revision <COMMIT_A>..<COMMIT_B> where
  COMMIT_B is not :WORKTREE: works too.
• Hide fatal error from Git on stderr when git show doesn't find the file in rev1.
  This isn't fatal from Darker's point of view since it's a newly created file.
• Use forward slash as the path separator when calling Git in Windows. At least
  git show and git cat-file fail when using backslashes.