fix user generation count

lib/populator/user_generator.rb

@@ -8,7 +8,8 @@ module Populator
     end
 
     def populate
-      total = (@total_count / (@store.duration / @store.iteration_duration).to_i).to_i
+      periods = (@store.duration / @store.iteration_duration).to_i
+      total = periods == @store.period ? @count : (@total_count / periods).to_i
       @count -= total
 
       # generate users