Create SecondGreatLow

Question: 
Have the function SecondGreatLow(arr) take the array of numbers stored in arr and return the second lowest and second greatest numbers, respectively, separated by a space. For example: if arr contains [7, 7, 12, 98, 106] the output should be 12 98. The array will not be empty and will contain at least 2 numbers. It can get tricky if there's just two numbers!
Merge pull request #4 from DCeppos/Easy

Create SecondGreatLow