Log Message:
py-w3lib: updated to 1.22.0

1.22.0:
- Python 3.4 is no longer supported
- :func:`w3lib.url.safe_url_string` now supports an optional ``quote_path``
  parameter to disable the percent-encoding of the URL path
- :func:`w3lib.url.add_or_replace_parameter` and
  :func:`w3lib.url.add_or_replace_parameters` no longer remove duplicate
  parameters from the original query string that are not being added or
  replaced
- :func:`w3lib.html.remove_tags` now raises a :exc:`ValueError` exception
  instead of :exc:`AssertionError` when using both the ``which_ones`` and the
  ``keep`` parameters
- Test improvements
- Documentation improvements
- Code cleanup