OSX/CI: kdev-ruby fails to build on branch master

[Marko Käning]

CMake Error at parser/CMakeLists.txt:35 (install):
  install TARGETS given no LIBRARY DESTINATION for shared library target
  "kdevrubyparser".


CMake Error at duchain/CMakeLists.txt:35 (install):
  install TARGETS given no LIBRARY DESTINATION for shared library target
  "kdevrubyduchain".


CMake Error at rails/CMakeLists.txt:27 (install):
  install TARGETS given no LIBRARY DESTINATION for shared library target
  "kdevrubyrails".


CMake Error at completion/CMakeLists.txt:34 (install):
  install TARGETS given no LIBRARY DESTINATION for shared library target
  "kdevrubycompletion".