Create a function that takes an array of numbers and return "Boom!" if the digit 7 appears in the array. Otherwise, return "there is no 7 in the array".
Examples:
sevenBoom([1, 2, 3, 4, 5, 6, 7]) ➞ "Boom!"
// 7 contains the number seven.
sevenBoom([8, 6, 33, 100]) ➞ "there is no 7 in the array"
// None of the items contain 7 within them.
sevenBoom([2, 55, 60, 97, 86]) ➞ "Boom!"
// 97 contains the number seven.