You are given a string and an array of single character strings as an argument. Return the shortest substring that can be found in the given string that contains every character in the array.
Assume all characters are lower case and that the substring will be at least two characters long.
- Must return a string
solve("environmental earth science", ["n","e","i","m"]) > "ironme"
'n', 'e', 'i' and 'm' can all be found in 'environmental' which is the shortest substring that can be made.