Add obstacle avoidance

src/obstacle_avoidance/obstacle_avoidance/__init__.py

...stacle_avoidance/obstacle_avoidance/obstacle_avoidance.py

src/obstacle_avoidance/package.xml

src/obstacle_avoidance/resource/obstacle_avoidance

src/obstacle_avoidance/setup.cfg

src/obstacle_avoidance/setup.py

src/obstacle_avoidance/test/test_copyright.py

src/obstacle_avoidance/test/test_flake8.py

src/obstacle_avoidance/test/test_pep257.py