Update builder.rb
Update builder.rb

Use double-quotes since we are referencing a variable
mattray/omnibus,Scalr/omnibus,ashhher3/omnibus,chef/omnibus,Altiscale/omnibus,higanworks/omnibus,rhass/omnibus,pskrz/omnibus,higanworks/omnibus,DataDog/omnibus-ruby,DataDog/omnibus-ruby,pskrz/omnibus,sh9189/omnibus,adamleff/omnibus,rhass/omnibus,intfrr/omnibus,strangelittlemonkey/omnibus,sh9189/omnibus,pskrz/omnibus,3ofcoins/chef-omnibus,rapid7/omnibus,chef/omnibus,DataDog/omnibus-ruby,mattray/omnibus,adamleff/omnibus,jamesn/omnibus,lvfeng1130/omnibus,strangelittlemonkey/omnibus,Altiscale/omnibus,mattray/omnibus,rhass/omnibus,sh9189/omnibus,ashhher3/omnibus,chef/omnibus,szechyjs/omnibus,rapid7/omnibus,hugosato/omnibus,szechyjs/omnibus,Altiscale/omnibus,jamesn/omnibus,Scalr/omnibus,3ofcoins/chef-omnibus,adamleff/omnibus,hugosato/omnibus,lvfeng1130/omnibus,intfrr/omnibus,szechyjs/omnibus,strangelittlemonkey/omnibus,rapid7/omnibus,jamesn/omnibus,3ofcoins/chef-omnibus,ashhher3/omnibus,lvfeng1130/omnibus,Scalr/omnibus,intfrr/omnibus,higanworks/omnibus,hugosato/omnibus