Removed all the poor documentation.
Introduced the IArticleCollector interface.
To fix ci strange error - even if CA1702 is already addressed with

the SuppressMessage attribute.
https://ci.appveyor.com/project/jwChung/articleharbor-webapidemo/build/123
Addressed that HaniRssCollector should implement the IArticleCollector

interface.
Introduced the FacebookRssCollector class.
Introduced the Actor and FacebookId properties.
Implemented the FacebookRssCollector class.