Remove Cliff completion command?

[zstumgoren]

Cliff provides a built-in command that appears to generate bash script/code to support autocompletion of specified commands.

If we keep the command, we should do some manual tests and document the workflow for using the command somewhere in the datakit docs.

Or we can remove this command to avoid confusion among non-expert users.

Removal would entail modifying an instance variable set by Cliff on the CommandManager:

# datakit/datakit_app.py
  class Datakit(App):

      def __init__(self, *args, **kwargs):
          super(Datakit, self).__init__(*args, **kwargs)
          self.command_manager.add_command('help', help.HelpCommand)
+         self.command_manager.commands.pop('complete')