Snapshot dependencies check should not fail if the only snapshot dependencies are test dependencies

[big-andy-coates]

Given test dependencies are not part of the release, failing if there are snapshot test dependencies seems unnecessarily strict, and may require users, (i.e. me! ;) ), to disable the snapshot check, when they'd actually like the snapshot check for release dependencies.

IMHO, snapshot test dependencies should be allowed.

[bgalek]

@big-andy-coates seems fair, wanna make PR that excludes testDependencies?

[big-andy-coates]

Hey @bgalek,

Thanks for the response.

Currently fixing an issue in Mockito. Will do my best to find the time... ;)