Use mockito version from commons-parent

[raboof]

replaces #514

this seems small enough not to need an entry in changes.xml, right?

• Read the contribution guidelines for this project.
• Run a successful build using the default Maven goal with mvn; that's mvn on the command line by itself.
• Write unit tests that match behavioral changes, where the tests fail if the changes to the runtime are not applied. This may not always be possible but is a best-practice.
• Write a pull request description that is detailed enough to understand what the pull request does, how, and why.
• Each commit in the pull request should have a meaningful subject line and body. Note that commits might be squashed by a maintainer on merge.

[garydgregory]

@raboof
I agree! Merged.