Handlers do not guarantee a numeric exit code; work around it (#96)

We currently don't have a safe guard for handlers to have a numeric exit code but they can return None.

In this patch we work around it until we can fix it.

pulse_actions/worker.py

@@ -260,10 +260,6 @@ def end_request(exit_code, data, log_path, treeherder_job, start_time):
         url = S3_UPLOADER.upload(log_path)
         LOG.debug('Log uploaded to {}'.format(url))
 
-        # XXX: Do something more elegant
-        if exit_code is None:
-            exit_code = 0
-
         JOB_FACTORY.submit_completed(
             job=treeherder_job,
             result=EXIT_CODE_JOB_RESULT_MAP[exit_code],
@@ -336,6 +332,10 @@ def _ignore_hack(data):
         exit_code = handler(data=data, message=message, repo_name=repo_name,
                             revision=revision, **kwargs)
 
+        # XXX: Until handlers can guarantee an exit_code
+        if exit_code is None:
+            exit_code = 0
+
         # 3) Submit results to Treeherder
         end_request(exit_code=exit_code, data=data, **end_request_kwargs)