Grouped UITableView has 20px of extra padding at the bottom

@frankWhite’ solution works great, but here is a better solution to avoid typing 0.1, 0.001 or others to make it less ambiguous.

// Swift version
func tableView(tableView: UITableView, heightForFooterInSection section: Int) -> CGFloat {

    // remove bottom extra 20px space.
    return CGFloat.min
}

// Objective-C version
- (CGFloat)tableView:(UITableView *)tableView heightForFooterInSection:(NSInteger)section {

    // remove bottom extra 20px space.
    return CGFLOAT_MIN;
}