Create a function that finds how many prime numbers there are, up to the given integer.
primeNumbers(10) ➞ 4 // 2, 3, 5 and 7 primeNumbers(20) ➞ 8 // 2, 3, 5, 7, 11, 13, 17 and 19 primeNumbers(30) ➞ 10 // 2, 3, 5, 7, 11, 13, 17, 19, 23 and 29
N/A