adding first version of x509less cmsxcache

[ddavila0]

• adds a fetch_scitoken script to fetch a scitoken from CMS. Reads Username/Pass from config file
• add cron job that calls the above
• modifies supervisord to add 2 env vars: BEARER_TOKEN_FILE and XrdSecPROTOCOL to make the cache o read using the token

This requires a change in 40-xcache-auth.cfg to to avoid setting the env var: X509_USER_PROXY