fix uuid to be 16-byte instead of 8-byte

Author: sunnygleason

src/main/java/org/sunnycode/hash/file2/UuidHelper.java

@@ -5,7 +5,7 @@
 
 public class UuidHelper {
     public static byte[] uuidToBytes(UUID uuid) {
-        ByteBuffer buf = ByteBuffer.allocate(8);
+        ByteBuffer buf = ByteBuffer.allocate(16);
 
         buf.putLong(uuid.getMostSignificantBits());
         buf.putLong(uuid.getLeastSignificantBits());