remove unused controllers and repositories

app/controllers/countries_controller.rb

app/controllers/edges_controller.rb

app/controllers/universities_controller.rb

app/repositories/active_record/country_repository.rb

app/repositories/active_record/university_repository.rb

app/repositories/orient_db/country_repository.rb

app/repositories/orient_db/edge_repository.rb

app/repositories/orient_db/university_repository.rb

app/views/countries/index.html.erb

app/views/countries/show.html.erb

app/views/universities/index.html.erb

app/views/universities/show.html.erb

config/initializers/repositories.rb

lib/orient_db/methods/edge_methods.rb