added migration, model to handle requests
added request model and test for it.
added requests controllers with index action, added tests for that
added validation to check the existence of receiver before save since rails does not do that for me. Added users controller with index and show action to list registered o single user + tests
added has_many :through to access a request's receiver's data
using user factory inside request factory
added pending_requests_controller to manage pending requests. added index to list and update to accept-reject
renamed resource request to appeal. listed list of friends. added tests
added friends controller. list my friends. accept deny requests
added support to show friends' messages