[BUILD] add github workflow

[bmarwell]

Just a suggestion. This way further pull requests will automatically be checked.

[bmarwell]

Because of the prompt, I was not able to add the "dist" goal. However, the signing could be done by a passphrase-less gpg key. This is needed for a rat-check. Skipped it for now.

[bmarwell]

Tests with other JDKs (11, 17, 21) can be added in another commit, if you are interested.

[ddekany]

Thanks! BTW, Travis ran very long ago, when it was still free, but it's green build icon is still there. If there something like that Git actions, it should be replaced to with that.

[bmarwell]

Sure! Can do that in another PR, preferably. Otherwise I'd do it blindly.

I would love to add the "ant dist" target. The only thing I can't do is "answer yes" on the last question.
I don't know much ant. But maybe we could add a build property which skips the interactive question on CI builds?

[bmarwell]

This PR should also remove Travis.

[bmarwell]

We can add a cache in a later PR, but for now this should be fine. Maybe not even worth it as the project is heading towards Gradle.

[ddekany]

We don't need ant dist, but ant ci, which I see you have discovered. If we want to test more, it should be added to ci. But, yes, these will go away with the Gradle PR anyway. (There's also Github actions prepared for that by the author of the Gradle PR).