Add /containers/stats response to API docs

Include the response schema for a succesful request in the
/containers/stats API documentation

Additionally remove http 409 from /libpod/containers/stats docs, the
documentation was copied from the deprecated stats endpoint, when a
container is unavailabe the endpoint returns an empty list and no 409.

Signed-off-by: Jelle van der Waa <jvanderwaa@redhat.com>

pkg/api/handlers/swagger/swagger.go

@@ -176,3 +176,12 @@ type swagInspectPodResponse struct {
 		define.InspectPodData
 	}
 }
+
+// Get stats for one or more containers
+// swagger:response ContainerStats
+type swagContainerStatsResponse struct {
+	// in:body
+	Body struct {
+		define.ContainerStats
+	}
+}

pkg/api/server/register_containers.go

@@ -1124,11 +1124,9 @@ func (s *APIServer) registerContainersHandlers(r *mux.Router) error {
 	// - application/json
 	// responses:
 	//   200:
-	//     description: no error
+	//     $ref: "#/responses/ContainerStats"
 	//   404:
 	//     $ref: "#/responses/NoSuchContainer"
-	//   409:
-	//     $ref: "#/responses/ConflictError"
 	//   500:
 	//     $ref: "#/responses/InternalError"
 	r.HandleFunc(VersionedPath("/libpod/containers/stats"), s.APIHandler(libpod.StatsContainer)).Methods(http.MethodGet)