Newsfeed Grade

Hey Ben, 
No worries since this is the last assignment, but instead of forking from the repository I think we ask you guys to clone from the repo that we made for you guys so we can make our comments for grading:
`git clone git@github.com:callbackjs/<username>-newsfeed.git` 

Sorry for any confusion, but I'm going to make my comments in this pull request if that's alright with you!

-Sherman
Nice job defining your postSchema