support all_tenants
Update test to recognize all_tenants parameter
Fix spacing between methods/examples for readability
Differentiate between admin and member session

We will use the admin session for the all_tenants test.
Add test for the all_tenants parameter
Comply with Travis Ci warning
Merge branch 'feature/volume_all_tenants'

This implements the all_tenants feature for querying
the volume service to get all volumes from all tenants.