Merge branch 'master' of github.com:web-push-libs/pywebpush into bug/18

Conflicts:
	pywebpush/__init__.py
	pywebpush/tests/test_webpush.py
	requirements.txt

Author: jrconlin

pywebpush/tests/test_webpush.py

@@ -119,7 +119,6 @@ def test_send_no_headers(self, mock_post):
         pheaders = mock_post.call_args[1].get('headers')
         eq_(pheaders.get('ttl'), '0')
         ok_('encryption' in pheaders)
-        ckey = pheaders.get('crypto-key')
         eq_(pheaders.get('content-encoding'), 'aesgcm')
 
     def test_ci_dict(self):