Enable key-duplicates yamllint check and adjust code

Change-Id: I4de2435ff5deabe10dcd9ecaf8f336bd369e8566

ceilometer/values.yaml

@@ -656,8 +656,6 @@ conf:
           fields: payload.audit_period_ending
     - event_type: trove.*
       traits: &trove_base_traits
-        state:
-          fields: payload.state_description
         instance_type:
           fields: payload.instance_type
         user_id:
@@ -1133,7 +1131,6 @@ conf:
           flavor_id: $.payload.instance_flavor_id
           flavor_name: $.payload.instance_type
           display_name: $.payload.display_name
-          host: $.payload.host
           image_ref: $.payload.image_meta.base_image_ref
       - name: 'vcpus'
         event_type: 'compute.instance.*'

yamllint.conf

@@ -32,8 +32,7 @@ rules:
     spaces: 2
     indent-sequences: whatever
     level: warning
-  key-duplicates:
-    level: warning
+  key-duplicates: enable
   key-ordering: disable
   line-length: disable
   new-line-at-end-of-file: