fully integrate mcnews lib into this package

[rahulbot]

After some work on #26, I think we should probably integrate the mcnews package into this one and delete that one. The logic here is that the other library is adding too many layers of abstraction when we need access to lower level information inside of this providers library. Previously, we had a lot of different API's that we were accessing so the abstractions made sense, but now they are just hurting us. That library is at https://github.com/mediacloud/mediacloud-news-client.