Swap to SleekXMPP-FS, a fork built specifically for sucks

This fork of SleekXMPP disables certificate validation to work around wpietri#62 and wpietri#45

This fix should be seen as a temporary hack until we figure out a long term solution.

setup.py

@@ -63,7 +63,7 @@
     # https://packaging.python.org/en/latest/requirements.html
 
     install_requires=[
-        'sleekxmpp>=1.3',
+        'sleekxmppfs>=1.3.4',
         'click>=6',
         'requests>=2.18',
         'pycryptodome>=3.4',

sucks/__init__.py

@@ -7,9 +7,9 @@
 
 import requests
 import stringcase
-from sleekxmpp import ClientXMPP, Callback, MatchXPath
-from sleekxmpp.xmlstream import ET
-from sleekxmpp.exceptions import XMPPError
+from sleekxmppfs import ClientXMPP, Callback, MatchXPath
+from sleekxmppfs.xmlstream import ET
+from sleekxmppfs.exceptions import XMPPError
 
 _LOGGER = logging.getLogger(__name__)