Merge pull request #869 from delbertlegg/549_Create_largest-series-product

Added stubs to LargestSeriesProductCalculator

exercises/largest-series-product/src/main/java/LargestSeriesProductCalculator.java

-public class LargestSeriesProductCalculator {
-
-
+class LargestSeriesProductCalculator {
+    LargestSeriesProductCalculator(String inputNumber) {
+        throw new UnsupportedOperationException ("Delete this statement and write your own implementation.");
+    }
 
+    long calculateLargestProductForSeriesLength(int numberOfDigits) {
+        throw new UnsupportedOperationException ("Delete this statement and write your own implementation.");
+    }
 }