added .lessOrEqual to Sortable

Author: marioplumbarius

src/main/java/io/github/marioluan/algorithms/sorting/Sortable.java

@@ -19,6 +19,19 @@ protected static boolean less(Comparable a, Comparable b) {
         return a.compareTo(b) < 0;
     }
 
+    /**
+     * Check whether {@link Comparable a} is lesser or equal to
+     * {@link Comparable b}.
+     *
+     * @param a
+     * @param b
+     * @return returns whether a is lesser or equal to b
+     */
+    @SuppressWarnings({ "rawtypes", "unchecked" })
+    protected static boolean lessOrEqual(Comparable a, Comparable b) {
+        return a.compareTo(b) < 1;
+    }
+
     /**
      * Swap item in position i by item in position j from array {@link a}.
      *