Add spec for UpdateCourseStats debugging
user
```ruby
# frozen_string_literal: true

require 'rails_helper'

describe UpdateCourseStats do
  let(:course) { create(:course, flags: flags) }
  let(:subject) { described_class.new(course) }

  context 'when debugging is not enabled' do
    let(:flags) { nil }
    it 'posts no Sentry logs' do
      expect(Raven).not_to receive(:capture_message)
      subject
    end
  end

  context 'when :debug_updates flag is set' do
    let(:flags) { { debug_updates: true } }
    it 'posts debug info to Sentry' do
      expect(Raven).to receive(:capture_message).exactly(5).times.and_call_original
      subject
    end
  end
end
```
assistant