Unit test fixes

src/__tests__/packet.test.js

@@ -4,7 +4,7 @@ test('can construct a packet', () => {
   const p = new packet('my password');
   console.log(p);
   expect(p.token).toEqual('my password');
-  expect(p.buffer).toBeNull();
+  expect(p.buffer).toEqual(new Uint8Array(0));
   expect(p.decode_offset).toEqual(0);
 });