CYB-251.   Honor 'active' flag for likes being scored.
   New 'like' records should store the current value of the active field
   PointsConfiguration record with their type (Like, Dislike, MarkNeutral)
   (Previously this field was not populated, and defaulted to false)
CYB-226 Engagement Index should be frequently, automatically, updated

  * introduces sidekiq and clockwork
  * sidekiq and clockwork are to be started from their own shell
  * scripts/clock.rb is the recipe for automatic execution