Feature: add depends flag for ament_python_install_package (#254)

Signed-off-by: = <elnadav12@gmail.com>

Author: nadavelkabets

rosidl_generator_py/cmake/rosidl_generator_py_generate_interfaces.cmake

@@ -134,12 +134,13 @@ rosidl_write_generator_arguments(
   TARGET_DEPENDENCIES ${target_dependencies}
 )
 
+set(_target_suffix "__py")
+
 if(NOT rosidl_generate_interfaces_SKIP_INSTALL)
-  ament_python_install_package(${PROJECT_NAME} PACKAGE_DIR "${_output_path}")
+  ament_python_install_package(${PROJECT_NAME} PACKAGE_DIR "${_output_path}"
+  DEPENDS ${rosidl_generate_interfaces_TARGET}${_target_suffix})
 endif()
 
-set(_target_suffix "__py")
-
 # move custom command into a subdirectory to avoid multiple invocations on Windows
 set(_subdir "${CMAKE_CURRENT_BINARY_DIR}/${rosidl_generate_interfaces_TARGET}${_target_suffix}")
 file(MAKE_DIRECTORY "${_subdir}")