Author: Joseph Wu
Revision Date: 2017-01-30 19:48:00 UTC

Windows: Lower the minimum CMake version to 3.6.0.

The Windows CMake build requires a few features of CMake 3.6,
but none of the existing 3.6 patch releases will affect the
Mesos build.

This also unblocks the ASF Windows CI build, which has 3.6.0.