add therubyracer gem to Gemfile.
add therubyracer gem to Gemfile.

davydovanton/sinatra,davydovanton/sinatra,sinatra/sinatra,gferguson-gd/sinatra,Rayheng/sinatra,emiliocorpus/sinatra,JonRowe/sinatra,autopp/sinatra,trexnix/sinatra,d-bot/sinatra,guidohcosta/sinatra,porras/sinatra,ABaldwinHunter/sinatra-classic,ktw1222/sinatra,ksw2599/sinatra,Callygraphy/morrissey,gferguson-gd/sinatra,kumji/sinatra,lastcat/sinatra,dariubs/sinatra,cyberid41/sinatra,midorineko/sinatra,defsprite/sinatra,burningTyger/sinatra,JonMidhir/sinatra,siberianbear/sinatra,guidohcosta/sinatra,dariubs/sinatra,eileencodes/sinatra,sethuster/sinatra,midorineko/sinatra,defsprite/sinatra,kyontan/sinatra,kyontan/sinatra,DoraALin/sinatra,autopp/sinatra,howtolearntocode/sinatra,nju520/sinatra,emiliocorpus/sinatra,laplaceliu/sinatra,QLGu/sinatra,jkowens/sinatra,JonMidhir/sinatra,Wirachmat/sinatra,laplaceliu/sinatra,JonRowe/sinatra,ganmacs/sinatra,nju520/sinatra,howtolearntocode/sinatra,sinatra/sinatra,burningTyger/sinatra,lastcat/sinatra,marocchino/sinatra,RosenDimov/sinatra,Rayheng/sinatra,jkowens/sinatra,d-bot/sinatra,ktw1222/sinatra,kumji/sinatra,jkowens/sinatra,wzheng1/sinatra,miyazawatomoka/sinatra,ABaldwinHunter/sinatra-classic,ryanshaw/sinatra,cyberid41/sinatra,JonMidhir/sinatra,trexnix/sinatra,mwpastore/sinatra,eileencodes/sinatra,mwpastore/sinatra,siberianbear/sinatra,frechei/sinatra,ganmacs/sinatra,Wirachmat/sinatra,ryanshaw/sinatra,jenalgit/sinatra,jenalgit/sinatra,nicoayala/sinatra,nicoayala/sinatra,QLGu/sinatra,porras/sinatra,ksw2599/sinatra,mwpastore/sinatra,RosenDimov/sinatra,kgrz/sinatra,DoraALin/sinatra,wzheng1/sinatra,sethuster/sinatra,miyazawatomoka/sinatra,burningTyger/sinatra,frechei/sinatra