Add Scala support

[oliver-brm]

Motivation:

Generating a project with the Scala language is currently not supported. This change adds Scala support with Maven and Gradle build systems.

Hint:

Before integrating this change, we need a release of Vert.x Scala support .

Closes #118

[tsegismont]

Thank you @oliver-brm !

Please ping me when the PR is ready for review

[tsegismont]

@oliver-brm have you merged this PR incidentally? There are some tests failures. In this case, can you please revert and fix the issues?

[oliver-brm]

@tsegismont I'm so sorry! I accidentally pushed to origin instead of my fork... How do we revert this? Seems like I have no permission to revert the PR. I'll check if I can create a reverting PR manually.

[oliver-brm]

@tsegismont sorry for the inconvenience again! I created a PR that reverts my mistake. Could you please check? -> #383

[tsegismont]

@tsegismont I'm so sorry! I accidentally pushed to origin instead of my fork... How do we revert this? Seems like I have no permission to revert the PR. I'll check if I can create a reverting PR manually.

No worries. I thought it was possible to revert PRs (I've seen this button in the past, but I can't find it).

Could you please check? -> #383

Done!