A git annex hook

For now it do nothing, but initialise in the session store the creds.
New dependency for the hook
Store username and appli id in public view

only secret should be secret.
Store the tokens to access to hubic.
A function to check if the creds are available
A class that connect to hubic
Changing initialisation of GitAnnexHook
Change to option when running from cli.
Fail when we don't know about the password.

We do it early to not polute stdout when run as a hook.
Connect to hubic.
Let's call main
use warn for message to the user
Ask for the container to be in the argument of the hook.
Dispatch in the hook class.
give the container to the hook
Add accessor for endpoint and token in hubic
A function to set the container
Storing for hubic
ENV['ANNEX_ACTION'] in a variable
Dispatch with the container