Add environment variable to set settings path (#328)

Co-authored-by: Zachary Ware <[email protected]>

Co-authored-by: Zachary Ware <[email protected]>

master/master.cfg

@@ -80,6 +80,7 @@ def set_up_sentry():
     log.addObserver(logToSentry)
 
 settings_path = os.path.join('/etc', 'buildbot', 'settings.yaml')
+settings_path = os.environ.get('PYBUILDBOT_SETTINGS_PATH', settings_path)
 
 try:
     settings = Settings.from_file(settings_path)