We use mocked Youtube server to check functionality related to YouTube failover. 
To check it we set some response time see [/video.feature#L39](https://github.com/edx/edx-platform/blob/8b19927753fd1ed6c0ed86fe42d5e20355aaadf7/lms/djangoapps/courseware/features/video.feature#L39). 
This response time is applied for all further scenarios. That's why I have added @after.each_scenario here.