Add "Unknown" value to health state enum

Dell iDrac returns "Unknown" health state when the server is powered off.

Change-Id: I6b1b35fa0a97afff110d11fb4d995210182ad6fd

api/mocks/RedfishAPI.go

@@ -1,4 +1,4 @@
-// Code generated by mockery v0.0.0-dev. DO NOT EDIT.
+// Code generated by mockery v2.7.4. DO NOT EDIT.
 
 package mocks
 

client/api/openapi.yaml

@@ -577,6 +577,7 @@ components:
       - OK
       - Warning
       - Critical
+      - Unknown
       type: string
     PowerState:
       enum:

client/docs/Health.md

@@ -9,6 +9,8 @@
 
 * `CRITICAL` (value: `"Critical"`)
 
+* `UNKNOWN` (value: `"Unknown"`)
+
 
 [[Back to Model list]](../README.md#documentation-for-models) [[Back to API list]](../README.md#documentation-for-api-endpoints) [[Back to README]](../README.md)
 

client/model_health.go

@@ -23,6 +23,7 @@ const (
 	HEALTH_OK Health = "OK"
 	HEALTH_WARNING Health = "Warning"
 	HEALTH_CRITICAL Health = "Critical"
+	HEALTH_UNKNOWN Health = "Unknown"
 )
 
 func (v *Health) UnmarshalJSON(src []byte) error {
@@ -32,7 +33,7 @@ func (v *Health) UnmarshalJSON(src []byte) error {
 		return err
 	}
 	enumTypeValue := Health(value)
-	for _, existing := range []Health{ "OK", "Warning", "Critical",   } {
+	for _, existing := range []Health{ "OK", "Warning", "Critical", "Unknown",   } {
 		if existing == enumTypeValue {
 			*v = enumTypeValue
 			return nil

spec/openapi.yaml

@@ -569,6 +569,7 @@ components:
       - OK
       - Warning
       - Critical
+      - Unknown
       type: string
     PowerState:
       enum: