Create Noetic dockerfiles

[mikaelarguedas]

These files won't compile just yet, because apparently the ROS bootstrap tools are not released in their python2 version for focal.

We'll need to modify the bootstrap tools template to not only use the ros_version but to also get the ROS_PYTHON_VERSION to install the tools accordingly. It would be great to get it from e.g. rosdistro rather than hard-coding it.

@sloretz FYI

[ruffsl]

Is that something we could put in the platform yaml? ros_python_version

[ruffsl]

Ah, thought you meant the template wouldn't compile the same Dockerfiles, as if you had patched them manually.

[mikaelarguedas]

As discussed offline with @ruffsl , right now we monkey-patch the dockerfile by hand to enable the initial release.

The better approach will be to use rosdistro to get the missing information. Follow-up tracking ticket at #406

[mikaelarguedas]

Images built and smoke-tested locally with:

source /opt/ros/noetic/setup.bash 
rosrun rospy_tutorials add_two_ints_server &
rosrun roscpp_tutorials add_two_ints_client 3 5

PR updated