Python3 migration

[tylerjw]

Description

This makes the move_group_python_interface_tutorial both python2 and python3 compatible. This is needed to run this tutorial on Noetic.

[rhaschke]

Thanks for starting this. There are other not yet python3 compliant python files though. Please handle them all:
doc/collision_environments/scripts/collision_scene_example.py
_scripts/tutorialformatter.py

[tylerjw]

Thanks for starting this. There are other not yet python3 compliant python files though. Please handle them all:
doc/collision_environments/scripts/collision_scene_example.py
_scripts/tutorialformatter.py

@rhaschke I updated this to include changes for collision_scene_example.py but was not able to find anything wrong with tutorialformatter.py. I also don't understand how tutorialformatter.py is used so I wasn't able to test it outside of just calling it with python3 (which runs without error and produces no output).

[rhaschke]

I was not able to find anything wrong with tutorialformatter.py.

Sorry for the noise. I was looking at an older version of the file. Michael already fixed some stuff a while ago (#410).

I also don't understand how tutorialformatter.py is used so I wasn't able to test it outside of just calling it with python3

It's used as a plugin to sphinx, generating the docs:
https://github.com/ros-planning/moveit_tutorials/blob/f0ac33f91603d7bffa8592d9a9b4943cec7eedea/conf.py#L5-L6