Sidekiq: Pass count through to yml file generator

[KieranP]

This allows us to dynamically set which queues to use in sidekiq.yml based on # of workers and the current count

---
:verbose: <%= @verbose %>
<% if @workers > 1 %>
<%# When there is more than one worker, the last one gets one thread reserved for %>
<%# low jobs and the rest of the threads divided up among the remaining jobs %>
<% if (@count + 1) < @workers %>
:concurrency: <%= (@concurrency / (@workers - 1)).ceil %>
:queues:
  - high
  - mailers
  - default
<% else %>
:concurrency: 1
:queues:
  - low
<% end %>
<% else %>
:concurrency: <%= (@concurrency / @workers).ceil %>
:queues:
  - high
  - mailers
  - default
  - low
<% end %>