add buildbot extension for autoscaling nix builders

buildbot-ext/buildbot_autoscale_ext/tests/__init__.py

@@ -0,0 +1,11 @@
+"""Tests for buildbot_autoscale_ext."""
+
+import asyncio
+from contextlib import suppress
+
+from twisted.internet import asyncioreactor
+
+TEST_LOOP = asyncio.new_event_loop()
+
+with suppress(Exception):
+    asyncioreactor.install(TEST_LOOP)