catch KeenApiError

[ruleant]

Traceback (most recent call last):
  File "/usr/local/lib/python2.7/dist-packages/cherrypy/_cprequest.py", line 670, in respond
    response.body = self.handler()
  File "/usr/local/lib/python2.7/dist-packages/cherrypy/lib/encoding.py", line 217, in __call__
    self.body = self.oldhandler(*args, **kwargs)
  File "/usr/local/lib/python2.7/dist-packages/cherrypy/_cpdispatch.py", line 61, in __call__
    return self.callable(*self.args, **self.kwargs)
  File "service.py", line 93, in badge
    duration = get_avg_buildtime(repo, interval)
  File "/home/dieter/buildtime-service/buildtimetrend/keenio.py", line 229, in get_avg_buildtime
    filters=[get_repo_filter(repo)]
  File "/usr/local/lib/python2.7/dist-packages/keen/__init__.py", line 165, in average
    interval=interval, filters=filters, group_by=group_by, target_property=target_property)
  File "/usr/local/lib/python2.7/dist-packages/keen/client.py", line 289, in average
    return self.api.query("average", params)
  File "/usr/local/lib/python2.7/dist-packages/keen/api.py", line 151, in query
    raise exceptions.KeenApiError(error)
KeenApiError: Error from Keen API. Details:
 Message: Resource not found.
Code: ResourceNotFoundError