Remove generated dependency-reduced-pom

[ctubbsii]

• Prevent unneeded dependency-reduced-pom.xml file from being generated by the
  shade plugin, and dirtying the source tree.

[ctubbsii]

This was a small portion of #191 which didn't get included. I figured I'd create a separate pull request for it, so it can be addressed/discussed separately. I'm not sure this file is actually needed for anything, and it can cause problems during builds. In general, plugins which modify the source tree can interfere with the behavior of other plugins. This file can be relocated by configuring the maven-shade-plugin properly, but that causes problems and is a known issue. I'd recommend just removing it.

I'd also recommend keeping the original jline jar in place, and having the shade plugin create a jar with the -shaded classifier (I can add that to this pull request, if you agree), and only in a profile (because shaded jars shouldn't be deployed by default, in most circumstances).

[gnodet]

Yeah, I didn't include it from the original PR because it actually modifies the dependencies of the uploaded pom.
If we want to not generate the modified pom, we need to fix the original one so that jansi is at the provided scope.

Maybe a better option would be to turn the project into a multi-module with the generation of both a non shaded jar (with a different name such as jline-core) and the jline shaded jar. This would keep compatibility.

[ctubbsii]

I'm not a big fan of having a shaded jar without the classifier -shaded, to clearly identify it as such, but the jline-core solution would preserve the existing name. TBH, though, I really like the simplicity of jline not being a multi-module project.

[gnodet]

I agree, but the only other way to not break compatibility is to defer to the next major version I think.