Prepare release 0.8.1

Refs: #5250
Change-Id: I99931c1300cd752554aea764e9688d027b5de29e
diff --git a/wscript b/wscript
index c3686e3..029be35 100644
--- a/wscript
+++ b/wscript
@@ -3,7 +3,7 @@
 from waflib import Context, Logs, Utils
 import os, subprocess
 
-VERSION = '0.8.0'
+VERSION = '0.8.1'
 APPNAME = 'ndn-cxx'
 GIT_TAG_PREFIX = 'ndn-cxx-'