In master gtest fails to build with the error
/home/travis/build/polybar/polybar/build/googletest-src/googlemock/include/gmock/gmock-more-actions.h:138:1: error: ISO C++11 requires at least one argument for the "..." in a variadic macro [-Werror]
ACTION_P(ReturnPointee, pointer) { return *pointer; }
We had a lot of failed builds because gtest often breaks stuff in
master. From now on we will just use a release tag. Whenever there is a
new release, we manually update this file.
Ref: google/googletest#2678