Merge pull request #1078 from m-a-ge/change_method_signature_in_reverse-string

Change reverse method signature to follow test requirements

exercises/reverse-string/src/main/java/ReverseString.java

 class ReverseString {
   
-    String reverse() {
+    String reverse(String stringToReverse) {
         throw new UnsupportedOperationException("Delete this statement and write your own implementation.");
     }