v0.7.0

This is the last release using Buildout for deployment.
This release will be maintained on the 0.7.x branch.

Issues solved:

• Fix async mode in demo service (#26)
• Fix WSGI app initialisation (#17)
• Use six for Python 2/3 compatibility (#20)
• Reference Readme in Sphinx docs (#22)
• Move tests/ folder to top-level directory (#21)
• Updated gunicorn 19.x (#19)