Fix bash syntax
Fix bash syntax

cinghiale/heroku-buildpack-nodejs-grunt-compass,willow-codes/heroku-buildpack-nodejs-bower-gulp-grunt-compass,greenapes/heroku-buildpack-nodejs-bower-gulp-grunt-compass,greenapes/heroku-buildpack-nodejs-bower-gulp-grunt-compass,artch/heroku-buildpack-nodejs-bower-gulp-grunt-compass