Fix sha56 byte count in protocol

test/hash_test.dart

@@ -6,4 +6,14 @@ void main() {
   test("Test md5", () {
     expect(Hashing.md5Hash("Hello World"), "b10a8db164e0754105b7a99be72e3fe5");
   });
+
+  test("Test sha256", () {
+    List<int> hsh = Hashing.sha256Sum([0x0A, 0x0B]);
+    print("Sha256 Length: ${hsh.length}");
+
+    print("Sha256 Hash: ${Hashing.bytes2Hash(hsh)}");
+
+    expect(Hashing.bytes2Hash(hsh),
+        "bea0b72e71bfe7f15a88c25305bf96a9681e34d3aabe0c9a1b7093cb32d8ff05");
+  });
 }