turtlesim for ROS2

[routiful]

I have been ported turtlesim node(including tutorials) to ROS2.
It works same as ROS but has some differences in tutorials.

Add some information when mimic node is started
(https://github.com/ROBOTIS-Platform/ros_tutorials/blob/f8b600d331060f39afc44436b3016d99a9fead97/turtlesim/tutorials/mimic.cpp#L15)

Add argument to add namespace in mimic node
(https://github.com/ROBOTIS-Platform/ros_tutorials/blob/f8b600d331060f39afc44436b3016d99a9fead97/turtlesim/tutorials/mimic.cpp#L64)

Add stop signal in turtle_teleop node
(https://github.com/ROBOTIS-Platform/ros_tutorials/blob/f8b600d331060f39afc44436b3016d99a9fead97/turtlesim/tutorials/teleop_turtle_key.cpp#L117)

Please review this and feel free to comment for anything.

[routiful]

Carefully Ping
I assured that turtlesim is the best simulation for ROS2 users.

[dirk-thomas]

I added some comments inline but didn't go through the whole patch for now. The general feedback:

• Please avoid any unnecessary changes in this patch (including style changes, refactorings, etc.). Only the bare minimum to convert from ROS 1 to ROS 2. The reason is to keep the dashing-devel branch as close to the melodic-devel branch as possible. Otherwise maintaining both branches moving forward will be much more effort.
• Any changes unrelated to the porting should be done in separate PRs. Preferably against the default branch from where they can be cherry-picked into the ROS 2 branch. Maybe consider getting them reviewed and merged first.

[routiful]

@dirk-thomas
Thank you for your review. I almost have accepted your required.
I have tested this in dashing-release.

[dirk-thomas]

I added another comment and some previous comments are still pending.

The main goal is to keep the diff as minimal as possible. So if a change isn't required to make it work with ROS 2 it shouldn't be part of this PR.

[routiful]

@dirk-thomas

Can you please enable the flag for allowing me to push changes to your branch.

I don't understand which means of flag. Could you describe to me more specific??

[dirk-thomas]

I don't understand which means of flag. Could you describe to me more specific??

https://help.github.com/en/articles/allowing-changes-to-a-pull-request-branch-created-from-a-fork

[routiful]

@dirk-thomas
Thanks. I'v enabled that check box.

[dirk-thomas]

CI confirms that the package build successfully on Linux / macOS (I doesn't have any tests):

• Linux
• Linux-aarch64
• macOS

On Windows it fails to build atm but that can be addressed in a separate PR:

• Windows

Thank you for iterating on this even though it took me a while to get back at it.