Fix resource set permission issue #171

[ddelnano]

This is a follow up to #172

Todo

• [x] Create non admin user for the test rather than relying on an existing user.
• [x] Remove hardcoding of the precreated user uuid. This is because non admin users cannot call user.getAll
• [x] Fix vm acceptance test that verifies resource sets can be created and updated
• [x] Ensure that the xen orchestra client properly logs the new resourceSet field in requests (using a pointer makes you believe that it is sending a pointer address to the XO api, but in reality it isn't)
• [x] make testacc passes

[ddelnano]

Since #180 was landed the acceptance tests are much flakier than they used to be. This is happens when a panic occurs during the acceptance tests and the non admin user is not cleaned up. A subsequent acceptance test run will fail when trying to create the user. This was a problem I identified in #84 and has become more painful over time as more tests have been added. But I think now is the appropriate time to fix this.