Corrected error in RandonKeyCipherTest.java

I changed the cipherKeysAreRandomlyGenerated test so that it does not compare the new Cipher to the length of the old Cipher.

simple-cipher/src/test/java/RandomKeyCipherTest.java

@@ -25,7 +25,7 @@ public class RandomKeyCipherTest {
 
     @Test
     public void cipherKeysAreRandomlyGenerated() {
-        assertTrue(!(new Cipher().getKey().equals(cipher.getKey().length())));
+        assertTrue(!(new Cipher().getKey().equals(cipher.getKey())));
     }
 
     /**