Revert "dont run c exts on jruby on travis"
Revert "dont run c exts on jruby on travis"

This reverts commit d24946a214c7d2a8b8f59bd8d2bd9db5569e9b21.

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