Initial setup
Add user model and serializer
Add articles model and serializer
Add tag model and serializer. Add hbtm association between tags and articles.
Add project model and serializer. Update user model for authentication.
Config database to postgresql
Add db seed and update typo for project model
Add pry-rails gem. Update validations for models. Add routes.
Create CRUD routes for models. Add markdown concern for articles
and projects.
Add model to santize tags when an article is updated/created.
Update CRUD actions of models.
Add api versioning filter. Add tags to article's json.