Rename cron_nightly_build to nightly

spec/factories/ci/trigger_schedules.rb

@@ -14,17 +14,17 @@ FactoryGirl.define do
       end
     end
 
-    trait :cron_nightly_build do
+    trait :nightly do
       cron '0 1 * * *'
       cron_time_zone Gitlab::Ci::CronParser::VALID_SYNTAX_SAMPLE_TIME_ZONE
     end
 
-    trait :cron_weekly_build do
+    trait :weekly do
       cron '0 1 * * 6'
       cron_time_zone Gitlab::Ci::CronParser::VALID_SYNTAX_SAMPLE_TIME_ZONE
     end
 
-    trait :cron_monthly_build do
+    trait :monthly do
       cron '0 1 22 * *'
       cron_time_zone Gitlab::Ci::CronParser::VALID_SYNTAX_SAMPLE_TIME_ZONE
     end

spec/models/ci/trigger_schedule_spec.rb

@@ -6,7 +6,7 @@ describe Ci::TriggerSchedule, models: true do
   it { is_expected.to respond_to :ref }
 
   describe '#schedule_next_run!' do
-    let(:trigger_schedule) { create(:ci_trigger_schedule, :cron_nightly_build, next_run_at: nil) }
+    let(:trigger_schedule) { create(:ci_trigger_schedule, :nightly, next_run_at: nil) }
 
     before do
       trigger_schedule.schedule_next_run!

spec/workers/trigger_schedule_worker_spec.rb

@@ -8,7 +8,7 @@ describe TriggerScheduleWorker do
   end
 
   context 'when there is a scheduled trigger within next_run_at' do
-    let!(:trigger_schedule) { create(:ci_trigger_schedule, :cron_nightly_build, :force_triggable) }
+    let!(:trigger_schedule) { create(:ci_trigger_schedule, :nightly, :force_triggable) }
 
     before do
       worker.perform
@@ -29,7 +29,7 @@ describe TriggerScheduleWorker do
   end
 
   context 'when there are no scheduled triggers within next_run_at' do
-    let!(:trigger_schedule) { create(:ci_trigger_schedule, :cron_nightly_build) }
+    let!(:trigger_schedule) { create(:ci_trigger_schedule, :nightly) }
 
     before do
       worker.perform