Add support in our Jenkins pipelines to run tests on a list of Python interpreter versions
Once we have support for multiple python interpreters in our CI images, we need to implement support for running tests against multiple python versions in our pipelines.
This should be effected on the following job templates:
- '{name}/gitlab-builds' (list of python versions to test)
- '{name}/master' (ditto)
- '{name}/pypi-upload' (list of python versions to test before upload)