Completed draft of new release plugin.

Need to add tests to flesh out and validate the behavior.
Move NearestVersion classes into semver package.
Adding test for ApplyAllChain
Adding test for ChooseOne
Consolidate partialsemverstrategy impls into the util.
Adding specs for SemVerStrategy selector
Adding test of happy path SemVerStrategy.infer
Remove use of spock-extensions since it isn't compatible with spock 1.0-SNAPSHOT
Add test for enforcePrecedence violation in SemVerStrategy.
Adding coverage for Strategies.Normal
Adding coverage for Strategies.PreRelease
Adding coverage for Strategies.BuildMetadata
Added coverage for Strategies.SNAPSHOT
Adding coverage for Strategies.DEVELOPMENT
Adding coverage for Strategies.PRE_RELEASE
Adding coverage to Strategies.FINAL
Adding coverage for TagStrategy
Adding coverage for BaseReleasePlugin.
Complete opinion plugin and supporting previous version on ReleaseVersion.
Added coverage for OpinionReleasePlugin