simplify test specification

before anyone starts copying from here...

Author: v4hn

demo/test/CMakeLists.txt

@@ -6,8 +6,6 @@
 if (CATKIN_ENABLE_TESTING)
   find_package(rostest REQUIRED)
 
-  add_executable(pick_place_test pick_place_test.cpp)
-  target_link_libraries(pick_place_test ${PROJECT_NAME}_pick_place_task ${catkin_LIBRARIES} gtest_main)
-
-  add_rostest(pick_place.test)
+  add_rostest_gtest(pick_place_test pick_place.test pick_place_test.cpp)
+  target_link_libraries(pick_place_test ${PROJECT_NAME}_pick_place_task ${catkin_LIBRARIES})
 endif()