automated test coverage report

[headupinclouds]

Using cmake...

• https://github.com/JoakimSoderberg/coveralls-cmake

• https://cmake.org/cmake/help/v3.2/module/CTestCoverageCollectGCOV.html

• http://stackoverflow.com/questions/39374827/ctest-generate-and-submit-gcov-tar-to-cdash-after-make-target

• llvm-cov support RWTH-HPC/CMake-codecov#5 (comment)

The standard gcc profiler options aren't recognized in my latest Xcode config...
HINT:

Currently, when I compile with CMake-codecov and clang it is compiled like this:

/usr/bin/clang++ -O0 -g -fprofile-arcs -ftest-coverage ...

In contrast, to use the native mode one would compile like this:

/usr/bin/clang++ -O0 -g -fprofile-instr-generate -fcoverage-mapping ...