CI Test in other distros

[spoltier]

Test whether Java dependencies are downloaded / detected properly in further Linux distributions (we are currently only testing on Ubuntu).

As expected, using containers we can't use the recommended actions for setting up java and R, and existing docker images are missing some of the dependencies we need (rocker - debian based - doesn't have java, there's an unmaintained centos7 + R image which probably we shouldn't use anyway).
See e.g. https://github.com/miraisolutions/xlconnect/actions/runs/536526701 and other actions failing on the same day.

My attempts at making GH actions work with containers are on branch https://github.com/miraisolutions/xlconnect/tree/custom/gh-actions-container.

images

We would need a red hat UBI / fedora, and a debian docker image for testing XLConnect. We can start from some rocker image for the debian case.

workflow

Use a separate CI workflow: need to install and run tests, since only that shows whether the java classpath contains all required dependencies. R CMD check is not required in my opinion.

Originally posted by @spoltier in #117 (comment)

[spoltier]

rhub/rhub2 allows running checks against fedora, which may help (though unclear how often it would be reasonable to run against r-hub's (hosted?) infra.