[Tubetk-developers] CMake Bump to 2.8.12

[Matt McCormick]

Hi,

To address a CMake warning, it would be easiest to use a feature in
CMake 2.8.12 (file(GENERATE ...)).  Is it OK to bump the required
CMake version?  Looking at the dashboard builds, there is a split
between 2.8.11 and 2.8.12, so some would need to be updated.

Thanks,
Matt