HTTP endpoint to return key information

Closes #6 (closed)

design/design.go

@@ -43,6 +43,17 @@ var _ = Service("signer", func() {
 			Response(StatusOK)
 		})
 	})
+
+	Method("GetKey", func() {
+		Description("GetKey returns key information from Vault or OCM.")
+		Payload(GetKeyRequest)
+		Result(Any)
+		HTTP(func() {
+			GET("/v1/keys/{key}")
+
+			Response(StatusOK)
+		})
+	})
 })
 
 var _ = Service("health", func() {