Feature/latest news

- Added ability to create an CMS page as an article. 
    - Besides adding the actual content to the page, you are expected to use the Article plugin to create an Article object. This Article object has the information such as the title, summary, published date, etc. Using this Article plugin is very important. We can discuss this part in details if something is not that clear.

- Added an endpoint to retrieve the latest news. By default if nothing is provided to the endpoint, two latest published article objects would be retrieved. The endpoint can also retrieve latest news related to a specific tournament, if tournament slug is being passed in the GET request. It's also possible to control the number of articles by passing a 'limit' parameter.
There is a possibility that an article is associated with more than one tournament. And if we want to get latest articles for a specific tournament then we need to know exactly which tournament this request is made so we grab the correct image_url.