Build and publish Javadoc to GitHub Pages using Travis CI

[filips123]

This builds and publishes Javadoc to GitHub Pages using Travis CI and closes #53.

Documentation will be built for every commit on master branch and automatically published to GitHub Pages of this repository. I deployed example version for my repository here.

To make this work, you will need to add GITHUB_TOKEN environment variable in Travis CI to make publishing to gh-pages branch work.

[Chew]

Could this be possible with GH Actions instead of a 3rd party service?

[filips123]

Yes. But I used Travis CI because it is already used for some other building and testing.

[Chew]

Ah makes sense, carry on then!

[nschmeller]

This should get merged in, it seems super useful!

[limwa]

I think I have found a typo. Other than that, looks good to me. Thank you for contributing.

[Andre601]

A question I'm sure maintainers would ask: Is a setup of Travic required for this to work?
If yes should it be considered to better use GitHub Actions rather than Travis. Otherwise, could it be used I guess...