Removing unneeded from __future__ import statements.

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

ebook_converter/customize/__init__.py

@@ -1,13 +1,13 @@
-from __future__ import absolute_import, division, print_function, unicode_literals
-__license__   = 'GPL v3'
-__copyright__ = '2008, Kovid Goyal <kovid at kovidgoyal.net>'
-
 import os, sys, zipfile, importlib
 
 from ebook_converter.constants import numeric_version, iswindows, isosx
 from ebook_converter.ptempfile import PersistentTemporaryFile
 from ebook_converter.polyglot.builtins import unicode_type
 
+
+__license__   = 'GPL v3'
+__copyright__ = '2008, Kovid Goyal <kovid at kovidgoyal.net>'
+
 platform = 'linux'
 if iswindows:
     platform = 'windows'