update version to 2.3.x for python2/3 support

setup.py

@@ -17,7 +17,7 @@ def get_version():
         rev = int(f.read().split()[0])
         f.close()
         if rev:
-            version = u"2.1.%s"%rev
+            version = u"2.3.%s"%rev
             with open(__version, 'w') as fd:
                 fd.write('VERSION="%s"'%version)
             return version
@@ -34,8 +34,8 @@ def get_version():
         f.close()
         rev = re.compile('\d+\.\d+\.(\d+)').findall(head)
         if rev:
-            return u'2.1.%s'%rev[0]
-    return u'2.1.x'
+            return u'2.3.%s'%rev[0]
+    return u'2.3.x'
 
 setup(
     name="ox",