Fix botogram crashing if someone edits a message

The Bot API 2.1 update (not supported by botogram 0.2.x) introduced a
new kind of Update when someone edits a message the bot knows about.
This allows to create cool things, but it isn't supported by botogram
0.2.x, since support for it was added in botogram 0.3.1.

Unfortunately, this meant botogram crashed when it received that kind
of update. This commit ignores every update other than the ones it
supports, so the fix lasts even for new kind of updates not introduced
yet.

Fixes: GH-70

Author: Pietro Albini

botogram/runner/processes.py

@@ -201,6 +201,11 @@ def loop(self):
             return
 
         for update in updates:
+            # botogram 0.2.x doesn't support anything but messages, ignore the
+            # other things -- Fix issue GH-70
+            if update.message is None:
+                continue
+
             self.last_id = update.update_id
 
             if not self.backlog_processed:

docs/changelog.rst

@@ -9,6 +9,17 @@ botogram changelog
 
 Here you can see what changed in every botogram release.
 
+.. _changelog-0.2.2:
+
+botogram 0.2.2
+==============
+
+*Bugfix release, not yet released*
+
+* Fix botogram crashing if someone edits a message (`issue 70`_)
+
+.. _issue 70: https://github.com/pietroalbini/botogram/issues/70
+
 .. _changelog-0.2.1:
 
 botogram 0.2.1