Failing test for 5
Now returning buzz for 5
Failing test for 6
Now returning fizz for multiples of 3
Wrote automatically passing test for 9
Wrote failing test for 10
Now returning buzz for multiples of 5
Wrote failing test for special case 15
Now returning fizzbuzz for multiples of both 3 and 5
Simplified logic for multiples of 15
Added additional tests for 20 and 30 for assurance