unfork ScalaMock

[SethTisue]

similar to #144

done in 2.11.x-jdk6 as of #147, but still needs to be pushed through to 2.11.x-jdk8 and 2.12.x

[SethTisue]

I have now seen green trial runs in all 3 builds, so even though it's not all merged through yet onto all branches (which may take a few days since the runs take so long), closing as done