Filter by scopes and paginate GET /projects
Define project attributes to be returned by serializer
Add :expires_at and attributes w/o html tags to ProjectSerializer
Allow filtering of projects by category and ordering
Allow projects filtering by created_at, expires_at and online_date
Allow querying projects
Document GET /projects endpoint
Use symbol keys in ProjectConcern
Check for permissions when returning projects
Include entire user object in ProjectSerializer
Update dependencies
Scope Api's Project logic inside Neighborly::Api module

Following this approach, we avoid conflicts between engines and keep the
"core" model (Project, in the main application) with less
responsibilities.

Against it, when using gems like has_scope and pundit, we need to
explicitly specify which constant we need to be used on instantianting
an object: Project or Neighborly::Api::Project (since they don't have
access to Ruby's scopes of constants by modules).
Remove search of projects by category id