CMakeFiles.txt lib dir is fixed

[jiangqii]

install(TARGETS ${PROJECT_NAME} EXPORT ${PROJECT_NAME}
  ARCHIVE DESTINATION lib
  LIBRARY DESTINATION lib
  RUNTIME DESTINATION bin)

This is not a dynamic change, it is recommended to use variables from cmake

install(TARGETS ${PROJECT_NAME} EXPORT ${PROJECT_NAME}
  ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
  LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
  RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR})

[clalancette]

This is not a dynamic change, it is recommended to use variables from cmake

From what I understand, we can only do this if we use GNUInstallDirs, which we don't currently do. We've had some discussions about switching to this (see ros2/ros2#1465), but we haven't gotten there yet.

I'm going to close this as a duplicate of ros2/ros2#1465