Add in some test_depend.

Signed-off-by: Chris Lalancette <[email protected]>

Author: clalancette

image_tools_py/package.xml

@@ -16,9 +16,11 @@
   <!-- These test dependencies are optional
   Their purpose is to make sure that the code passes the linters -->
   <test_depend>ament_copyright</test_depend>
+  <test_depend>ament_flake8</test_depend>
   <test_depend>ament_pep257</test_depend>
   <test_depend>ament_pep8</test_depend>
   <test_depend>ament_pyflakes</test_depend>
+  <test_depend>launch</test_depend>
 
   <export>
     <build_type>ament_python</build_type>