Remove legacy bash wrapper

[iranzo]

Hi,
As the bash wrapper is falling behind on features, we should remove it to make it easier for users and update relevant documentation about using 'citellus.py' one

[iranzo]

After discussion, this will be left as a 'basic' fallback script which may be missing some of the other features in citellus.py

[zerodayz]

Removed the bash wrapper from the README.md, yet we decide to keep it as the fallback. The python is go-forward client now.