Travis-CI and multiple languages

[cheelee]

It is starting to seem like a single Sandbox for encapsulating an experimentation environment for multiple random/arbitrary project management features is not a common github idiom.

I had thought it would be easy to just add a battery of octave-related build/tests via Travis-CI to the current Sandbox configuration, but this wouldn't work with language: python, and there's (quite reasonably) no current way to specify multiple languages to Travis-CI. Some appropriate discussions are occurring here:

travis-ci/travis-ci#4090