function ok(value, message) {
  if (!value) {
    fail(value, true, message, "==", assert.ok);
  }
}
Node.js standard [`assert.ok`](http://nodejs.org/api/assert.html#assert_assert_value_message_assert_ok_value_message).
@static
@memberOf should
@category assertion assert
@param {*} value
@param {string} [message]