Apparently, media ids are strings

Nevermind that they are returned as integers from the same APIs, they
need to be passed as strings.

postgresqleu/util/messaging/twitter.py

@@ -249,7 +249,7 @@ def post(self, tweet, image=None, replytotweetid=None):
             if r.status_code != 200:
                 return (None, 'Media upload: {}'.format(r.text))
             d['media'] = {
-                'media_ids': [r.json()['media_id'], ]
+                'media_ids': [str(r.json()['media_id']), ]
             }
 
         while d['text']: