Continuous integration: simple framework to test C++ against Octave

I have octave scripts and C++ source code in 2 different git repositories.

1. I would like for every C++ commit - execute regression test suite (cmake/ctest based), which matches C++ output against octave output.
2. And for every octave commit - run octave and generate output and run C++ regression suit - see #1.

What is the simplest way to achieve that? Some simple/lightweight CI system?

Any suggestions?