Emphasize progress with ball holder of IT Dept.

app/assets/stylesheets/style.css
- Add '.in_it_dept'.
app/helpers/application_helper.rb
- Alter ball_holder_display() to return with HTML class of
  'in_it_dept' if progress.in_it_dept?() is true.
app/models/progress.rb
- Add in_it_dept?().
'progresses#index' to use cycle() to alternating table row apperance

app/views/progresses/index.html.erb
- Use cycle() to display table rows in alternating background color.