Move run.sh to a python file to be environment-agnostic

[CasperWA]

It may be prudent to move from the current run.sh file to a run.py similar to this one written by @fekad.

This will make it easier to develop in a Windows environment as well, but mostly simply remove any obvious OS environment dependency, although it may still be present indirectly.

[fekad]

It could be useful for debugging in PyCharm (which available for any OS) as well. As far as I know, you cannot activate the visual debuger mode when you run it from the bash.

[CasperWA]

If this is done, one should be aware that the location of local_*openapi.json files will most likely change. One should take care not to change the default location (which is the package root).

[CasperWA]

Adding a __name__ = '__main__' section to main.py, importing unicorn within the if-sentence will support debugging and development in a broader sense, while not disturbing other development frameworks.

[fekad]

This is an old issue and with the current structure of the tool, it doesn't make sense to do modifications.