Add minimum compatible version to --version command

[joaoCeilandia]

Proposed changes:

• Add MINIMUM-COMPATIBLE-VERSION to --version command.
• Resolves Expose MINIMUM_COMPATIBLE_VERSION in rasa version's output #7477

Status (please check what you already did):

• added some tests for the functionality
• updated the documentation
• updated the changelog (please check changelog for instructions)
• reformat files using black (please check Readme for instructions)

[sara-tagger]

Thanks for submitting a pull request 🚀 @melindaloubser1 will take a look at it as soon as possible ✨

[indam23]

Thanks for contributing!
Minor thing: Could you set the spacing so that the versions all line up like before? Right now it looks like this:

Rasa Version     : 2.4.0
Minimum Compatible Version     : 2.2.0a1
Rasa SDK Version : 2.4.0
Rasa X Version   : None
Python Version   : 3.7.4

something like this:

Rasa Version      :         2.4.0
Minimum Compatible Version: 2.2.0a1
Rasa SDK Version  :         2.4.0
Rasa X Version    :         None
Python Version    :         3.7.4

[joaoCeilandia]

@melindaloubser1 done!

[indam23]

🚀

[joaoCeilandia]

@melindaloubser1 this check is failling and i don't know why. Could you give me a hint?

[indam23]

It says

rasa/__main__.py:95:1: D103 Missing docstring in public function

This is because of a check introduced some months ago that requires docstrings be added to any new or changed functions.
Not sure why it picks up main() as changed - probably because of the surrounding lines - but you can use the existing comment on line 96 as the docstring e.g.

def main() -> None:
     """Run as standalone python application"""

[indam23]

Suggested change

	"""Running as standalone python application"""
	"""Run as standalone python application"""

By convention we use the imperative