Removing unneeded from __future__ import statements.

Since we are on Python 3.6 and up, we don't need those anymore.

ebook_converter/polyglot/binary.py

@@ -1,9 +1,3 @@
-#!/usr/bin/env python2
-# vim:fileencoding=utf-8
-# License: GPL v3 Copyright: 2019, Kovid Goyal <kovid at kovidgoyal.net>
-
-from __future__ import absolute_import, division, print_function, unicode_literals
-
 from base64 import standard_b64decode, standard_b64encode
 from binascii import hexlify, unhexlify