Create a function that accepts a list of numbers and return both the minimum and maximum numbers, in that order (as a list).
min_max([1, 2, 3, 4, 5]) ➞ [1, 5]
min_max([2334454, 5]) ➞ [5, 2334454]
min_max([1]) ➞ [1, 1]
All test lists will have at least one element and are valid.