Always use OrderedDict from collections, and remove its implementation in slixmpp.thirdparty.

tests/test_stanza_element.py

@@ -1,7 +1,7 @@
 import unittest
 from slixmpp.test import SlixTest
 from slixmpp.xmlstream.stanzabase import ElementBase, register_stanza_plugin, ET
-from slixmpp.thirdparty import OrderedDict
+from collections import OrderedDict
 
 
 class TestElementBase(SlixTest):

tests/test_stanza_xep_0004.py

@@ -1,7 +1,7 @@
 import unittest
 from slixmpp import Message
 from slixmpp.test import SlixTest
-from slixmpp.thirdparty import OrderedDict
+from collections import OrderedDict
 
 import slixmpp.plugins.xep_0004 as xep_0004
 from slixmpp.xmlstream import register_stanza_plugin