In todays exercise we want to revisit the idea of merging. That is, given two sorted arrays like the following we must merge them into one sorted array.
array_1 = [5,8,9,11]
array_2 = [4,6,7,10]
merge(array_1, array_2)
# => [4,5,6,7,8,9,10,11]
Given this brief discription, implement the merge method that takes two arrays and returns the properly sorted array containing the items from each array.