Replace couchbase counters with drb version

lib/qwaiter/couchbase.rb

@@ -5,13 +5,20 @@ module Qwaiter
     end
 
     def self.load_design_docs!
+      return unless connection.present?
       Dir.glob(Rails.root.join('config/couchbase/design_docs', "*.json")).each do |design_doc|
         connection.save_design_doc File.open(design_doc)
       end
     end
 
     def self.design_doc(name)
+      return unless connection.present?
       connection.design_docs[name]
     end
+
+    def self.flush_counters!
+      return unless connection.present?
+      design_doc('supplier').counters(reduce: false).each{|counter| Qwaiter::Counter.set counter.key, 0}
+    end
   end
 end