make patch version pinning operational with older Python
diff --git a/CHANGES.txt b/CHANGES.txt
index 2f613ef..0c47875 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -2,7 +2,7 @@
 Revision 0.1.2, released 07-09-2017
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-- Pinned to pyasn1 0.3.4+
+- Pinned to pyasn1 ~0.3.4
 
 Revision 0.1.1, released 27-08-2017
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