Fix Scheduler::SubscriptionsScheduler (#2834)

* Fix Scheduler::SubscriptionsScheduler, add worker test for it

* Change production log level of Sidekiq to "warn" instead of "info"

spec/workers/scheduler/subscriptions_scheduler_spec.rb

@@ -0,0 +1,19 @@
+require 'rails_helper'
+
+describe Scheduler::SubscriptionsScheduler do
+  subject { Scheduler::SubscriptionsScheduler.new }
+
+  let!(:expiring_account1) { Fabricate(:account, subscription_expires_at: 20.minutes.from_now, domain: 'example.com', followers_count: 1, hub_url: 'http://hub.example.com') }
+  let!(:expiring_account2) { Fabricate(:account, subscription_expires_at: 4.hours.from_now, domain: 'example.org', followers_count: 1, hub_url: 'http://hub.example.org') }
+
+  before do
+    stub_request(:post, 'http://hub.example.com/').to_return(status: 202)
+    stub_request(:post, 'http://hub.example.org/').to_return(status: 202)
+  end
+
+  it 're-subscribes for all expiring accounts' do
+    subject.perform
+    expect(a_request(:post, 'http://hub.example.com/')).to have_been_made.once
+    expect(a_request(:post, 'http://hub.example.org/')).to have_been_made.once
+  end
+end