Update test-vars.yml for repositories

Renamed in os_gnocchi role repo
Changed test-vars.yml to os_gnocchi-overrides.yml
Removed the test-vars.yml

Change-Id: I62ee2338f6bfeee06511a3077e11ed1e84baa66c
Partial-Bug: #1629284

tests/test-gnocchi-functional.yml

@@ -108,5 +108,3 @@
       assert:
         that:
           - "policies_retrieval.json | length >= 3"
-  vars_files:
-    - test-vars.yml

tests/test-install-gnocchi.yml

@@ -46,4 +46,3 @@
     - role: "os_gnocchi"
   vars_files:
     - common/test-vars.yml
-    - test-vars.yml

tox.ini

@@ -136,6 +136,7 @@ deps =
 commands =
     {[testenv:ansible]commands}
     ansible-playbook -i {toxinidir}/tests/inventory \
+                     -e @{toxinidir}/tests/os_gnocchi-overrides.yml \
                      {toxinidir}/tests/test.yml -vvvv
     {[testenv:func_logs]commands}