Print out new tag after tagging new release

[JoshMcCullough]

After e.g. ./gradlew tag -Prelease (or any variety that ends up creating a tag), simply output the created tag to the terminal so we don't have to then do git tag to find which tag was just created.

Example:

$ ./gradlew tag -Prelease -PnewPreRelease

Created new tag: 1.2.3-ALPHA.0

BUILD SUCCESSFUL in 916ms
1 actionable task: 1 executed

$ ./gradlew tag -Prelease -PpromoteToRelease

Created new tag: 1.2.3

BUILD SUCCESSFUL in 875ms
1 actionable task: 1 executed