Merge branch '22974-trigger-service-events-through-api' into 'master'

app/helpers/services_helper.rb

app/models/project_services/asana_service.rb

app/models/project_services/assembla_service.rb

app/models/project_services/bamboo_service.rb

app/models/project_services/bugzilla_service.rb

app/models/project_services/buildkite_service.rb

app/models/project_services/builds_email_service.rb

app/models/project_services/campfire_service.rb

app/models/project_services/chat_notification_service.rb

app/models/project_services/chat_slash_commands_service.rb

app/models/project_services/ci_service.rb

app/models/project_services/custom_issue_tracker_service.rb

app/models/project_services/deployment_service.rb

app/models/project_services/drone_ci_service.rb

app/models/project_services/emails_on_push_service.rb

app/models/project_services/external_wiki_service.rb

app/models/project_services/flowdock_service.rb

app/models/project_services/gemnasium_service.rb

app/models/project_services/gitlab_issue_tracker_service.rb

app/models/project_services/hipchat_service.rb