Add test for volume list with all-tenants

Add test for volume list with all-tenants param

Change-Id: Idc605ce5036090fe086164cdc24d8fe36b09f866
Separate negative tests for test_templates

Move negative tests from test_templates.py to test_templates_negative.py

Partially implements blueprint negative-test-files

Change-Id: I893ca188f54627f44bcd14c7c2ba6481561a9d1d
Merge "Add test for volume list with all-tenants"
Merge "Separate negative tests for test_templates"