fix typo in doc
fix typo in doc

mjalkio/AIESEC-NTP-Website,erikmajlath/ruby_quiz,yaph/coderstats,Askedio/Sinatra_Decent_Blog,Askedio/Sinatra_Decent_Blog,yaph/coderstats,erikmajlath/ruby_quiz,GiantRobotLabs/fitbuddy-gympass-server,mjalkio/AIESEC-NTP-Website,Askedio/Sinatra_Decent_Blog,Askedio/Sinatra_Decent_Blog,Askedio/Sinatra_Decent_Blog,mjalkio/AIESEC-NTP-Website,erikmajlath/ruby_quiz,mjalkio/AIESEC-NTP-Website,GiantRobotLabs/fitbuddy-gympass-server,yaph/coderstats