Fix issue with reputation attribute on User getting set to the API request reputation method

@thomas-mcdonald not sure if you want to accept this, but just making the issue known.

`#<Serel::User:70106256894280 @user_id=1749024, @user_type=registered, @creation_date=2012-10-15 22:29:34 -0700, @display_name=liamneesonsarmsauce, @profile_image=https://www.gravatar.com/avatar/87dcde02e2f35930e9a6a3e239f2ec81?d=identicon&r=PG, @reputation=#<Serel::Relation:0x007f85c5147650>, @reputation_change_day=50, @reputation_change_week=50, @reputation_change_month=190, @reputation_change_quarter=190, @reputation_change_year=245, @age=24, @last_access_date=2013-07-15 18:26:47 -0700, @last_modified_date=2013-07-15 16:35:05 -0700, @is_employee=false, @link=http://stackoverflow.com/users/1749024/liamneesonsarmsauce, @website_url=http://liamneesonsarm.com, @location=San Francisco, CA, @account_id=1943367, @badge_counts={"gold"=>0, "silver"=>0, "bronze"=>9} >`