Fix remaining selenium py3 test failures

[mvdbeek]

Should fix

selenium.webdriver.remote.remote_connection DEBUG 2018-08-16 19:17:13,852 Finished Request
galaxy.web.framework.decorators ERROR 2018-08-16 19:17:13,858 Uncaught exception in exposed API method:
Traceback (most recent call last):
  File "/galaxy/lib/galaxy/web/framework/decorators.py", line 157, in decorator
    rval = func(self, trans, *args, **kwargs)
  File "/galaxy/lib/galaxy/web/framework/decorators.py", line 77, in decorator
    return func(self, trans, *args, **kwargs)
  File "/galaxy/lib/galaxy/webapps/galaxy/controllers/history.py", line 317, in list
    return self.stored_list_grid(trans, **kwargs)
  File "/galaxy/lib/galaxy/web/framework/helpers/grids.py", line 139, in __call__
    query = column.filter(trans, trans.user, query, column_filter)
  File "/galaxy/lib/galaxy/web/framework/helpers/grids.py", line 664, in filter
    query = query.filter(self.get_filter(trans, user, column_filter))
  File "/galaxy/lib/galaxy/web/framework/helpers/grids.py", line 703, in get_filter
    raw_tags = trans.app.tag_handler.parse_tags(column_filter.encode("utf-8"))
  File "/galaxy/lib/galaxy/managers/tags.py", line 260, in parse_tags
    raw_tags = reg_exp.split(tag_str)
TypeError: cannot use a string pattern on a bytes-like object

xref. #1715

[mvdbeek]

We're down to 3 failures with python3: https://jenkins.galaxyproject.org/job/docker-selenium-py3/17/testReport/ -- 2 of these also fail on python 2. It's the generate test_generate_tour_with_data that is specific to python 3