Update minimum required version of python-twitter

Signed-off-by: Jim Easterbrook <jim@jim-easterbrook.me.uk>

setup.py

@@ -214,7 +214,7 @@ def run(self):
       extras_require = {
           'daemon'  : ['python-daemon'],
           'sftp'    : ['paramiko', 'pycrypto'],
-          'twitter' : ['python-twitter >= 1.0', 'oauth2'],
+          'twitter' : ['python-twitter >= 2.1', 'oauth2'],
           },
       zip_safe = False,
       use_2to3 = True,

src/doc/essentials/dependencies.rst

@@ -1,6 +1,6 @@
 .. pywws - Python software for USB Wireless Weather Stations
    http://github.com/jim-easterbrook/pywws
-   Copyright (C) 2008-15  pywws contributors
+   Copyright (C) 2008-16  pywws contributors
 
    This program is free software; you can redistribute it and/or
    modify it under the terms of the GNU General Public License
@@ -171,7 +171,7 @@ Twitter updates
 The :py:mod:`pywws.ToTwitter` module can be used to send weather status messages to Twitter.
 Posting to Twitter requires these modules:
 
-*  `python-twitter <https://github.com/bear/python-twitter>`_ v1.0 or higher
+*  `python-twitter <https://github.com/bear/python-twitter>`_ v2.1 or higher
 *  `python-oauth2 <https://github.com/simplegeo/python-oauth2>`_
 
 ::

src/pywws/__init__.py

@@ -1,3 +1,3 @@
 __version__ = '16.04.0'
-_release = '1350'
-_commit = 'c27c690'
+_release = '1351'
+_commit = '8b68e6f'