Pin splinter version as 0.7.0 has changed switch_to_window.
Switch from Paste to python3 compatible wsgi components
First pass at Python 3 compatibility.
All but one 'not bdd' test now passes. That error is only a test artefact due to https://github.com/gawel/WSGIProxy2/issues/7.
Needed to remove wal-e as that is blocked by gevent. It can be moved to a separate buildout or virtualenv.