Kb lc user add rubygem

Completed all user stories up to deleting a gem
This won't actually add the two timestamp columns you want, `created_at` and `updated_at` -- it'll only add 1 column called `timestamps`.  

Generate a new migration to remove this column and add the correct timestamp columns.  Check out this StackO question on how to do that: http://stackoverflow.com/questions/7542976/add-timestamps-to-an-existing-table  (there are a couple of ways).