Remove MavenDependencyResolver

[bethcutler]

See discussion in #445.

Basically, the Maven source seems to be a large dependency in ktlint for a small feature that may not be frequently used. I think we should consider removing this dependency.

[shashachu]

Makes total sense to me. Anyone who needs a custom reporter can run it from a local jar.

[Tapchicoma]

I would propose to do it gracefully - for next release print warning message with a link to this issue, whenever 3rd party rule/reporter dependency is requested

If nobody will provide solid arguments why it should stay - remove it in the release after.

[shashachu]

I would propose to do it gracefully - for next release print warning message with a link to this issue, whenever 3rd party rule/reporter dependency is requested

If nobody will provide solid arguments why it should stay - remove it in the release after.

That's a great idea.

[MaxAller]

When is this going to be released? We're actively waiting on this change :)