Add support for COURSE_WORK_CHANGES for google classroom feed

[rtcoms]

Fix for issue #704

There was no support for Feed type COURSE_WORK_CHANGES as mentioned here : https://developers.google.com/classroom/reference/rest/v1/registrations#FeedType

Added support for that by creating class CourseWorkChangesInfo and supporting attribute course_work_changes_info for class Feed

[coveralls]

Coverage remained the same at ?% when pulling d40b91d on rtcoms:support-course-work-changes-for-classroom-feed into 24be95a on google:master.

[dazuma]

This has been taken care of. The automated update was stuck due to some upstream dependency issues, but this has been resolved. Sorry for the delay.

[rtcoms]

@dazuma I don't understand what exactly you mean. Yesterday when I looked at the code, there was no code for CourseWorkChangesInfo, although now I see that it is there, so how that code got into master without merging the PR ?

[dazuma]

@rtcoms Normally, this repository is updated by an automated process that regenerates the client code based on changes to the discovery documents. (If you look at the commit history, those are the commits done by "googleapis-publisher".) The automation was broken for a few weeks, so the update here wasn't being pushed properly, but we just got it fixed yesterday.