removing ccache from cmake

[conjam]

seeing issues with ccache when using CMake -- removed it as per #737.

[coveralls]

Coverage remained the same at 93.699% when pulling 032e3e1 on conjam:remove_ccache_cmake into 6bc55ec on open-source-parsers:master.

[dota17]

@conjam
Thanks for your PR.
But from #737 (comment), is it better to change to not search outside $PATH?

[ClausKlein]

NO! I use ccache on very project.
see too https://github.com/ClausKlein/build-performance/blob/master/README.rst#and-build-performance-with-a-real-project

[conjam]

@conjam
Thanks for your PR.
But from #737 (comment), is it better to change to not search outside $PATH?

from my understanding, find_program() in cmake has ... issues. I played around with setting PATH, but it still breaks my build, even with the work around mentioned in the thread (I was trying to use bazel wrapping cmake). In the end I just ported this to bazel -- could submit PR if you like, figure that would just cause you headaches down the road.

Regardless, a better fix seems to be in so I'll close this