Richest customer wealth

#[test]
fn t1() {
    let start = std::time::Instant::now();
    let val = Solution::maximum_wealth(vv(&[&[1,2,3],&[3,2,1]]));
    let expected = 6;
    log_result!(val == expected, "t1", start, &expected, &val);
    assert_eq!(val, expected);
}

#[test]
fn t2() {
    let start = std::time::Instant::now();
    let val = Solution::maximum_wealth(vv(&[&[1,5],&[7,3],&[3,5]]));
    let expected = 10;
    log_result!(val == expected, "t2", start, &expected, &val);
    assert_eq!(val, expected);
}

#[test]
fn t3() {
    let start = std::time::Instant::now();
    let val = Solution::maximum_wealth(vv(&[&[2,8,7],&[7,1,3],&[1,9,5]]));
    let expected = 17;
    log_result!(val == expected, "t3", start, &expected, &val);
    assert_eq!(val, expected);
}

#[test]
fn t4() {
    let start = std::time::Instant::now();
    let val = Solution::maximum_wealth(vv(&[&[100]]));
    let expected = 100;
    log_result!(val == expected, "t4", start, &expected, &val);
    assert_eq!(val, expected);
}

#[test]
fn t5() {
    let start = std::time::Instant::now();
    let val = Solution::maximum_wealth(vv(&[&[1,2],&[3,4],&[5,6]]));
    let expected = 11;
    log_result!(val == expected, "t5", start, &expected, &val);
    assert_eq!(val, expected);
}