[fix] Heroku re-deploy issue with node-sass
[fix] Heroku re-deploy issue with node-sass

When deploying over an already-deployed app in heroku, binaries in the `vendor` directory of module `node-sass` disappear.
This extra post-installation step will force a fetch, for the application to start properly.
erood/weight_tracker_app,vymarkov/hackathon-starter,devneel/spitsomebars,peterblazejewicz/hackathon-starter,devneel/spitsomebars,quazar11/portfolio,stenio123/ai-hackathon,ericmreid/pingypong,ak-zul/hackathon-starter,stenio123/ai-hackathon,crystalrood/piggie,JessedeGit/vegtable,erood/weight_tracker_app,crystalrood/piggie,niallobrien/hackathon-starter-plus,OperationSpark/Hackathon-Angel,ericmreid/pingypong,OperationSpark/Hackathon-Angel,sahat/hackathon-starter,awarn/cashier-analytics,ReadingPlus/flog,sahat/hackathon-starter,crystalrood/piggie,HappyGenes/HappyGenes,HappyGenes/HappyGenes,vymarkov/hackathon-starter,ak-zul/hackathon-starter,quazar11/portfolio,peterblazejewicz/hackathon-starter,sahat/hackathon-starter,awarn/cashier-analytics,peterblazejewicz/hackathon-starter,niallobrien/hackathon-starter-plus,ReadingPlus/flog,JessedeGit/vegtable