added code format/style test and fixed up code

I converted all instances of `'''` to `"""` because PEP267 uses the double-quotes.

I also moved the param types into the `:param <type> <name>:` format.

Fix PEP8 things in a few places.
And I assume it should run multiple checks:

* https://github.com/ament/ament_lint/blob/4c0d0e8a7c4ab7b663087da59564a95f1038f83c/ament_pep8/bin/ament_pep8
* https://github.com/ament/ament_lint/blob/4c0d0e8a7c4ab7b663087da59564a95f1038f83c/ament_pyflakes/bin/ament_pyflakes
* https://github.com/ament/ament_lint/blob/4c0d0e8a7c4ab7b663087da59564a95f1038f83c/ament_copyright/bin/ament_copyright