v1.22.0

• Python 3.4 is no longer supported (issue #156)
• w3lib.url.safe_url_string now supports an optional quote_path
  parameter to disable the percent-encoding of the URL path (issue #119)
• w3lib.url.add_or_replace_parameter and
  w3lib.url.add_or_replace_parameters no longer remove duplicate
  parameters from the original query string that are not being added or
  replaced (issue #126)
• w3lib.html.remove_tags now raises a ValueError exception
  instead of AssertionError when using both the which_ones and the
  keep parameters (issue #154)
• Test improvements (issues #143, #146, #148, #149)
• Documentation improvements (issues #140, #144, #145, #151, #152, #153)
• Code cleanup (issue #139)