message: update tf.summary.merge_all()'s api  check
diff: @@ -50,7 +50,7 @@ tf_module {
  }
  member_method {
  name: "merge_all"
  - argspec: "args=[\'key\', \'scope\'], varargs=None, keywords=None, defaults=[\'summaries\', \'None\'], "
  + argspec: "args=[\'key\', \'scope\', \'name\'], varargs=None, keywords=None, defaults=[\'summaries\', \'None\', \'None\'], "
  }
  member_method {
  name: "scalar"
  