Write a function that returns all the elements in an array that are strictly greater than their adjacent left and right neighbors.
miniPeaks([4, 5, 2, 1, 4, 9, 7, 2]) ➞ [5, 9]
// 5 has neighbours 4 and 2, both are less than 5.
miniPeaks([1, 2, 1, 1, 3, 2, 5, 4, 4]) ➞ [2, 3, 5]
miniPeaks([1, 2, 3, 4, 5, 6]) ➞ []