Add ROS 2 integration tests

[EzraBrooks]

We'd like to release roslibjs v2 with a lot of improvements (asynchronous Services, ROS 2 Actions, ROS 2 TFClient), but we don't yet have any integration tests in CI for the ROS 2 support. Once this is done, we can release v2!

[sauk2]

What do you think about using setup-ros instead of the current approach followed for ROS 1?

[EzraBrooks]

That makes sense to me. I figure we'll eventually remove the ROS 1 jobs once ROS 1 is deprecated, so we don't need to create a CI matrix that covers both ROS 1 and ROS 2 - they can be separate jobs with separate implementations.

[ganatrask]

Hey @EzraBrooks I'd like to work on this issue can you share more details on what things need to be added for tests or CI for ROS?

[EzraBrooks]

The bulk of the work is to add ROS 2 versions of test/build.bash and .github/workflows/main.yml.

[labbomb]

It's been going on for a while, and now it's stuck? When will this milestone be released

[EzraBrooks]

As you can see from the milestone, this is the last remaining issue. Feel free to submit a PR!