anchor.diff:  
     - name: rbx-<%= RUBIES[:rbx].last %>-pr
       public: true
  +    serial_groups: [pr]
       plan:
         - get: loofah-pr
           trigger: true
  
positive.code: 
    - name: pr-success
      public: true
      disable_manual_trigger: true
      plan:
        - get: loofah-pr
  
negative.code: 
    - name: jruby-<%= RUBIES[:jruby].last %>-pr
      public: true
      serial_groups: [pr]
      plan:
        - get: loofah-pr
          trigger: true
  