Remove version numbers that made the plugin refuse to install in Kepler.
Merge pull request #881 from dragos/issue/kepler-deps

Remove version numbers that made the plugin refuse to install in Kepler.
Fixes StackOverflowError in `RegionUtils.subtract`

There are two problems in the underlying method `subtractImpl`:

- It calls the API method `subtract`, which is an unnecessary
  performance cost because `subtract` checks its input parameters
- It is not tail recursive

Fixes #1002361