CI should try to install

To detect errors such as removed files in the CMakeLists.txt, we should test sudo make install

I think this check is already performed when running cmake, is it not? If you have put some file in CMakeLists.txt and the file is no longer there I think cmake complains.

In the case that the missing .h file doesn't have a corresponding .cpp, nobody complains. It just happened to me.

closed via commit 810c53ab

mentioned in commit 810c53ab