Run 2to3 -f future . -w

This will remove imports from __future__ that are no longer needed.

https://docs.python.org/3.5/library/2to3.html#2to3fixer-future

docs/api/conf.py

@@ -6,7 +6,7 @@
 # full list see the documentation:
 # http://www.sphinx-doc.org/en/master/config
 
-from __future__ import absolute_import, unicode_literals
+
 
 import os