Fix #168 - prevent panic when calling ServerById() on non-existent resource
diff --git a/servers.go b/servers.go
index a00577e..425853b 100644
--- a/servers.go
+++ b/servers.go
@@ -86,6 +86,7 @@
 			MoreHeaders: map[string]string{
 				"X-Auth-Token": gsp.access.AuthToken(),
 			},
+			OkCodes: []int{200},
 		})
 	})