Implement Article Model, CRUD Routes, Decorators and Schemas

[Bryan Wong]

Is your feature request related to a problem? Please describe.
Integrate the Article feature by creating the model, routes, decorators and schemas.

Describe the solution you'd like

• Create Article model
• Create ArticleForm Schema and ArticleSchema with Marshmallow
• Implement Article routes
• Implement decorators

List of issues need to be complete

• #5
• #6

Miscellaneous

• Document Article model in Gitbooks in the Database models page.
• Test routes and document them in Postman, in a folder called Articles