Generate projects without Gradle

[tsegismont]

This PR removes the need for the backend generator (based on Gradle).

Instead, it uses the Vert.x template engine, Vert.x filesystem and Apache Commons Compress (no TAR support in the JDK).

[tsegismont]

Also, it fixes #66

[danielpetisme]

Thanks for this huge refactoring effot 👏 .

Finally we go back to the the templating option 🤔 obviously it looks easier to integrate but a bit harder to debug. Do you think we can provide some tests to check the project generations (with the Gradle backend I used to generate the matrix combination, trigger each generation and run the default build, test actions).

[tsegismont]

Thanks for this huge refactoring effort

You're welcome :)

Finally we go back to the the templating option thinking obviously it looks easier to integrate but a bit harder to debug.

The current Gradle backend also relies on templating. In this regard, it is not much different.

Do you think we can provide some tests to check the project generations (with the Gradle backend I used to generate the matrix combination, trigger each generation and run the default build, test actions).

Do you mean, build the generated project before sending it back to the client?

[jponge]

@tsegismont we already have #31 😉

[tsegismont]

Perfect.

[jponge]

LGTM

[tsegismont]

Thanks @jponge