round-off weight value while returing grading policy

TNL-884
@waheedahmed @mlkwaqas @adampalay 
Fix issue where when a user tries to set weight to some specific value e.g, '29' then 'jsonize_grader' method returns it as floating point '28.999999999999996' and displaying it on front end gives '28' instead of '29'
I see. I wonder if we should be doing the same thing (Math.round instead of parseInt) for min_count and drop_count to be consistent.