Added specs for PayrollCalculator#calculate method
Added methods to PayrollController#run method

I added the #get_payday and #print_list_of_dates, which I didn't do earlier. Also made a new instance of the controller with instance variables to test #print_list_of_dates
Changed Strings to Integers

I changed the way the paydays were stored in the controller from strings to integers representing the days of the week, so I had to change the tests accordingly.
Added hash with days of the week represented as integers
Extended Date class

I extended the date class with a few methods to make my life easier: A method that finds the start of a week, one that finds the start of the next week, one that finds the next certain weekday, one that finds the start of the previous week, and one that finds a certain weekday in the previous week
Gave the PayrollController#initialize method optional parameters to make it easier to test the controller
Commented out the statements puts-ing the instance variables and un commented #print_list_of_dates
Added the PayrollCalculator.calculate method
Instead of a hard-coded array, for day of week verification I just made it check the keys of the WEEK_DAYS hash
Changed 'friday' to 5 when setting default payday
Removed useless line
Removed useless puts statment
Merge pull request #5 from RyanVerhey/calculator

Calculator