fix ament not registering executables as tests

Author: Rid0n

tests/CMakeLists.txt

@@ -37,7 +37,7 @@ if(ament_cmake_FOUND AND BUILD_TESTING)
 
     find_package(ament_cmake_gtest REQUIRED)
 
-    ament_add_gtest_executable(${BTCPP_LIBRARY}_test ${BT_TESTS})
+    ament_add_gtest(${BTCPP_LIBRARY}_test ${BT_TESTS})
     target_link_libraries(${BTCPP_LIBRARY}_test
         ${TEST_DEPENDECIES}
         ${ament_LIBRARIES})