Removing unneeded from __future__ import statements.

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

ebook_converter/css_selectors/errors.py

@@ -1,18 +1,17 @@
-#!/usr/bin/env python2
-# vim:fileencoding=utf-8
-from __future__ import absolute_import, division, print_function, unicode_literals
-
 __license__ = 'GPL v3'
 __copyright__ = '2015, Kovid Goyal <kovid at kovidgoyal.net>'
 
+
 class SelectorError(ValueError):
 
     """Common parent for SelectorSyntaxError and ExpressionError"""
 
+
 class SelectorSyntaxError(SelectorError):
 
     """Parsing a selector that does not match the grammar."""
 
+
 class ExpressionError(SelectorError):
 
     """Unknown or unsupported selector (eg. pseudo-class)."""