FIP calculations and more data request abilities

Here are some changes/additions I made to allow for more requests from the server, in particular for pitchers.  Also created method to calculate pitcher FIP.  I'm a relative newbie to Ruby so feel free to adjust/give feedback on any of this.

I'm having a terrible time getting the gemfile to build correctly and cannot just use 'require 'pitcher'' in my tests when I build/install the gemfile myself, have you had luck building/installing the gemfile on your end?