Make __future__ imports consistent for better compat between 2 and 3
diff --git a/asn1crypto/ocsp.py b/asn1crypto/ocsp.py
index 18a2e03..e5bd5db 100644
--- a/asn1crypto/ocsp.py
+++ b/asn1crypto/ocsp.py
@@ -10,7 +10,7 @@
 Other type classes are defined that help compose the types listed above.
 """
 
-from __future__ import unicode_literals
+from __future__ import unicode_literals, division, absolute_import, print_function
 
 from .algos import DigestAlgorithm, SignedDigestAlgorithm
 from .core import (