[test/aes] Fix on python 3.3 and higher

Since 878563c847fa5248eedbd44187536dec04643eaf the aes functions only accepts the base64 data as a unicode string.

test/test_aes.py

@@ -39,7 +39,7 @@ class TestAES(unittest.TestCase):
         encrypted = base64.b64encode(
             intlist_to_bytes(self.iv[:8]) +
             b'\x17\x15\x93\xab\x8d\x80V\xcdV\xe0\t\xcdo\xc2\xa5\xd8ksM\r\xe27N\xae'
-        )
+        ).decode('utf-8')
         decrypted = (aes_decrypt_text(encrypted, password, 16))
         self.assertEqual(decrypted, self.secret_msg)
 
@@ -47,7 +47,7 @@ class TestAES(unittest.TestCase):
         encrypted = base64.b64encode(
             intlist_to_bytes(self.iv[:8]) +
             b'\x0b\xe6\xa4\xd9z\x0e\xb8\xb9\xd0\xd4i_\x85\x1d\x99\x98_\xe5\x80\xe7.\xbf\xa5\x83'
-        )
+        ).decode('utf-8')
         decrypted = (aes_decrypt_text(encrypted, password, 32))
         self.assertEqual(decrypted, self.secret_msg)