[Compute] Improved how bare metal flag is handled
[Compute] Fixed Exception when saving Server and setting bare_metal flag twice
[Compute] Refactored servers to set bare_metal flag without touch Excon responses
Minor fix on returning response
Minor fix to handling empty array
Small fix for unecessary check if array is empty
Fix bare metal test so it works without FOG_MOCK.
Fix bug with Compute bare_metal changes.