Add basic test.

[danhper]

I added a short test (if we can call that a test), to allow Travis to check multiple Python versions. It should help avoiding regressions. https://travis-ci.org/tuvistavie/bass/builds/89736654

[edc]

Awesome!

One potentially dumb question about Travis: when we set the python version to, say, 3.5, does it then alias python to python3.5?

[danhper]

Travis uses virtualenv to manage Python versions, so I suppose it does something like this:

virtualenv -p /path/to/python3.5/bin/python /path/to/project
source /path/to/project/bin/activate

which does more or less something like this.

• Create /path/to/project/bin, /path/to/project/include, /path/to/project/lib with everything needed to run Python (3.5 here), copied from /path/to/python3.5/bin/python (and its include and lib directories), and add some scripts to prepend /path/to/project/bin to the path
• Source the script to prepend /path/to/project/bin to the path, making the python in /path/to/project/bin the first on the path, therefore the default version.

Edit: After looking at the build log, it seems that a virtualenv already exists per Python version, so the virtualenv -p step is probably already done, and when running the build, it only needs to source the desired version's virtualenv bin/activate script.

[edc]

Nice! Thanks for making this.

[danhper]

No problem! Don't forget to add the repository to Travis so that PR are checked automatically!