Only .yaml files are loaded, not .yml

[blag]

Files using the .yml file extension are not picked up by the RBAC backend, even though they are valid YAML files and that is a valid YAML file extension.

2021-05-11 15:33:16,873 INFO [-] Loading role definitions from "/opt/stackstorm/rbac/roles/"
2021-05-11 15:33:16,873 INFO [-] Loading user role assignments from "/opt/stackstorm/rbac/assignments/"
2021-05-11 15:33:16,874 INFO [-] Loading group to role map definitions from "/opt/stackstorm/rbac/mappings/"
2021-05-11 15:33:16,874 INFO [-] Synchronizing roles...

After renaming to use .yaml:

2021-05-11 15:33:36,197 INFO [-] Loading role definitions from "/opt/stackstorm/rbac/roles/"
2021-05-11 15:33:36,197 INFO [-] Loading user role assignments from "/opt/stackstorm/rbac/assignments/"
2021-05-11 15:33:36,197 INFO [-] Loading group to role map definitions from "/opt/stackstorm/rbac/mappings/"
2021-05-11 15:33:36,197 DEBUG [-] Loading group to role mapping from: /opt/stackstorm/rbac/mappings/stormers.yaml
2021-05-11 15:33:36,263 INFO [-] Synchronizing roles...