message: Allow .optional ClassProperty nodes.
diff: @@ -1261,6 +1261,10 @@ function genericPrintNoParens(path, options, print) {
  parts.push(key);
  + if (n.optional) {
  + parts.push("?");
  + }
  +
  if (n.typeAnnotation) {
  parts.push(path.call(print, "typeAnnotation"));
  }
  