title: ActiveAdmin :select drop-down defaults to current value in development but defaults to blank in production
body: <p>I have the following ActiveAdmin form:</p>
  
  <pre><code>form do |f|
    f.inputs "Timesheet Details" do
      f.input :jobs_assigned_worker, :label =&gt; "Worker", as: :select, collection: Worker.all
      f.input :worked_time_hours,    :label =&gt; "Worked Time (Hours)"
      f.input :worked_time_mins,     :label =&gt; "Worked Time (Minutes)"
      f.input :driving_time_hours,   :label =&gt; "Driving Time (Hours)"
      f.input :driving_time_mins,    :label =&gt; "Driving Time (Minutes)"
      f.input :spent_dollars,        :label =&gt; "Extra Money Spent"
    end
    f.actions
  end
  </code></pre>
  
  <p>When I use this form in the edit view, the select drop-down automatically defaults to the present value. However in production the drop-down is for some reason defaulting to the blank value at the top (why is that blank value there anyway?). </p>
  
  <p><strong>EDIT</strong> </p>
  
  <p>The problem seems to be that ActiveAdmin doesn't understand the association and is unable to select associated object by default. I need to figure out how to code the <code>f.input</code> for the association. The form is for a Timesheet. A Timesheet <code>has_many</code> JobsAssignedWorkers and each JobsAssignedWorker has a Worker.</p>