Prepare 0.5.6 release

ChangeLog

+python-nbxmpp 0.5.6 (03 June 2017)
+
+  * Support XEP-0198 Version 1.5.2
+  * Add new XEP Namespaces
+
 python-nbxmpp 0.5.5 (30 January 2017)
 
   * Some cleanup

nbxmpp/__init__.py

@@ -17,4 +17,4 @@ from .client_nb import NonBlockingClient
 from .plugin import PlugIn
 from .smacks import Smacks
 
-__version__ = "0.5.5"
+__version__ = "0.5.6"

setup.py

@@ -3,7 +3,7 @@
 from distutils.core import setup
 
 setup(name='nbxmpp',
-      version='0.5.5',
+      version='0.5.6',
       description='Non blocking Jabber/XMPP module',
       author='Yann Leboulanger',
       author_email='asterix@lagaule.org',