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.
I am not sure if it is a good idea to duplicate that kind of snippet in every package. That should be done by the new ament_lint packages.