Add Python 3.6 to test matrix

[behave]

Add Python 3.6 to test matrix

[bittner]

Do you have an error message we can look at?

The issue you're mentioning does not affect Python 3.5 for our test runs. It may well be that simply specifying 3.6 in tox.ini and the Travis configuration makes it all work. As per travis-ci/docs-travis-ci-com#903 Python 3.6 is supported.

Let me note again that I would prefer to remove the explicit mentioning of basepython, which is implicitly supported by tox. Would be one thing less we need to update in the tox configuration.

[bittner]

Django 1.11 will be the first release supporting Python 3.6. So, we still have time to address the issue.

[mixxorz]

Turns out, our tests were only working because:

• We set python: 3.5 which means travis will explicitly install Python 3.5 on the test vm
• The base image Travis uses includes Python 2.7, 3.3, and 3.4

So when I set python to 3.6, tests running on 3.5 broke because it couldn't find that instance. The only way we can get the python versions we want is to specify multiple versions in .travis.yml, but it isn't that straightforward because we're using tox and... it was 11pm and I wanted to sleep so I gave up. 😆

I'll push up a new branch and you can take a look at what I did.

[bittner]

Testing against Python 3.5 and 3.6 on the same build image is now possible. Do you want to give that a shot again, @mixxorz?

[bittner]

Any plans to give it a shot again, @mixxorz?