Verify that access to the ESCAPE storage area is forbidden to anonymous clients

[andreaceccanti]

Verify that for anonymous clients (i.e., no ESCAPE VOMS proxy, no token)

• listing directories is forbidden
• reading files is forbidden
  • create a file using VOMS auth and try to read it anonymously
• writing files is forbidden
• creating directories is forbidden
• deleting files is forbidden
• removing directories is forbidden

[federicaagostini]

PR #10