Get a single bug object. Similar to python-bugzilla's getbugsimple().

        param bugid: integer, a bug's number.
        returns: deferred that when fired returns an AttrDict representing this
                 bug.

def get_bug_simple(self, bugid):
        """
        Get a single bug object. Similar to python-bugzilla's getbugsimple().

        param bugid: integer, a bug's number.
        returns: deferred that when fired returns an AttrDict representing this
                 bug.
        """
        payload = {'ids': bugid}
        d = self.call('Bug.get', payload)
        d.addCallback(self._parse_bug_callback)
        return d