Fix double roster entry issue with Unicode.

JIDs with Unicode values were being encoded by the JID class
instead of leaving them as just Unicode strings.

It may still be a good idea to use

    from __future__ import unicode_literals

pretty much everywhere though.

Fixes issue #88.

sleekxmpp/test/sleektest.py

@@ -16,7 +16,8 @@ import sleekxmpp
 from sleekxmpp import ClientXMPP, ComponentXMPP
 from sleekxmpp.stanza import Message, Iq, Presence
 from sleekxmpp.test import TestSocket, TestLiveSocket
-from sleekxmpp.xmlstream import StanzaBase, ET, register_stanza_plugin
+from sleekxmpp.xmlstream import ET, register_stanza_plugin
+from sleekxmpp.xmlstream import ElementBase, StanzaBase
 from sleekxmpp.xmlstream.tostring import tostring
 from sleekxmpp.xmlstream.matcher import StanzaPath, MatcherId
 from sleekxmpp.xmlstream.matcher import MatchXMLMask, MatchXPath
@@ -201,7 +202,7 @@ class SleekTest(unittest.TestCase):
                     "Stanza:\n%s" % str(stanza))
         else:
             stanza_class = stanza.__class__
-            if isinstance(criteria, str):
+            if not isinstance(criteria, ElementBase):
                 xml = self.parse_xml(criteria)
             else:
                 xml = criteria.xml
@@ -606,7 +607,7 @@ class SleekTest(unittest.TestCase):
             self.fail("Stanza data was sent: %s" % sent)
         if sent is None:
             self.fail("No stanza was sent.")
-        
+
         xml = self.parse_xml(sent)
         self.fix_namespaces(xml, 'jabber:client')
         sent = self.xmpp._build_stanza(xml, 'jabber:client')