Make haml --check work.
Make haml --check work.

It wasn't properly requiring the stringio library.

Andrey-Pavlov/sass,danielfein/sass,Nzaga/sass,modulexcite/sass,MetaAshley/sass,askl56/sass,chriseppstein/sass,stefanpenner/haml,StephanieMak/sass,StephanieMak/sass,oss-practice/sass,sideci-sample/sideci-sample-haml,stanhu/haml,PMArtz92/sass,HugoRLopes/sass,keithpitty/haml,zaru/sass,tangposmarvin/haml,haml/haml,jaroot32/sass,Andrey-Pavlov/sass,Anshdesire/sass,saper/sass,tenderlove/sass,schneems/sass,keithpitty/haml,saper/sass,haml/haml,srawlins/sass,lmetla/sass,cmpereirasi/sass,purcell/haml,antonifs/sass,dg1dd1ngs/haml,Anshdesire/sass,HugoRLopes/sass,vio/haml,hcatlin/sass,stanhu/haml,tangposmarvin/sass,ridixcr/sass,haml/haml,14113/sass,ridixcr/sass,rammy7219/sass,liquidmetal/sass,amatsuda/haml,macressler/haml,uniba/hamldoc_ja,Industrys/sass,Galactix/sass,modulexcite/sass,antonifs/sass,Iamronan/sass,JuanitoFatas/sass,concord-consortium/haml,nicklima/sass,nazar-pc/haml,hcatlin/sass,macressler/haml,askl56/sass,Ahnita/sass,stewx/sass,DanteKaris/sass,nazar-pc/haml,tangposmarvin/haml,jaroot32/sass,xzyfer/sass,srinivashappy/sass,dg1dd1ngs/haml,amitsuroliya/sass,JuanitoFatas/sass,Ahnita/sass,rammy7219/sass,lmetla/sass,chriseppstein/haml,amitsuroliya/sass,Iamronan/sass,chriseppstein/haml,cmpereirasi/sass,dylannnn/sass,xzyfer/sass,nicklima/sass,Industrys/sass,srawlins/sass,PMArtz92/sass,OrenBochman/sass,OrenBochman/sass,DanteKaris/sass,danielfein/sass,schneems/sass,mislav/haml,nickg33/sass,stewx/sass,srinivashappy/sass,Galactix/sass,dylannnn/sass,haml/haml,briangonzalez/sass,tangposmarvin/sass,MetaAshley/sass,liquidmetal/sass,baiyanghese/sass,zaru/sass,Nzaga/sass,nickg33/sass