Add galaxy.yml status check for pr's

[salob]

When we submit a pr we need to update the version in galaxy.yml. We could implement a quick check in Travis (or some other way?) to check if the version has been incremented or at the very least that the file has been changed.

[andreyzher]

One way of doing this is to only publish when the repository is tagged, rather than on merge to the main branch - a flow that is pretty common for many projects.

[andreyzher]

I believe I have this flow implemented using GitHub Actions on my fork (some parts are only done in theory as they require credentials to be configured under Settings -> Secrets):

main...andreyzher:gh-actions

• .github/workflows/molecule.yaml - the matrix build that executes the molecule scenarios in parallel - runs for all branches within the IBM-owned repo, but not on forks, as these would not have permissions to access the secrets
• .github/workflows/sanity.yaml - sanity / integration tests that can be run as a separate parallel as this covers the entire collection, not per molecule scenario
• .github/workflows/release.yaml - publish to galaxy and create a GitHub Release for the created tag

This, of course, assumes that the team would be willing to adopt the use of GitHub Actions instead of Travis. I'm going to leave the fork & branch there for reference.