Engine api spec tests

Fixed some rspec api controller tests to work with the enginification branch.

Following controllers were addressed under /katello/spec/controllers/api/
activation_keys_controller_spec.rb
changesets_content_controller_spec.rb
changesets_controller_spec.rb
content_views_controller_spec.rb
content_view_definitions_controller_spec.rb
custom_info_controller_spec.rb
distributions_controller_spec.rb
environments_controller_spec.rb
errata_controller_spec.rb
gpg_keys_controller_spec.rb
organization_default_info_controller_spec.rb
organizations_controller_spec.rb
packages_controller_spec.rb
permissions_controller_spec.rb
ping_controller_spec.rb
products_controller_spec.rb
repositories_controller_spec.rb
roles_controller_spec.rb
root_controller_spec.rb
subscriptions_controller_spec.rb
sync_controller_spec.rb
sync_plans_controller_spec.rb
system_group_errata_controller_spec.rb
system_group_packages_controller_spec.rb
system_groups_controller_spec.rb
systems_controller_spec.rb
systems_packages_controller_spec.rb
tasks_controller_spec.rb
uebercerts_controller_spec.rb
users_controller_spec.rb
providers_controller_spec.rb