0.15

• Added format_func argument to most of the providers. This allows to
  control which formatter function will be used as a default formatter.
  Previously it has been faker.provider.Python.pystr_format, which has
  been changed to faker.provider.Python.parse, since the latter is
  more convenient (as it does not transform characters
  like ?, !, # into something else using bothify method).
  To revert this behaviour, make sure to pass a callable
  function faker_file.base.pystr_format_func in format_func argument
  to each correspondent provider or inner function.
• Added create_inner_random_file_from_dir inner function.
• Tested against Django 4.2.
• Stop testing against Django 2.2.