Use single quotes in main `rpmbuild` command
Use single quotes in main `rpmbuild` command

This stops nesting of double quotes in in scenarios where the RPM is 
signed.

servebox/omnibus,DataDog/omnibus-ruby,hugosato/omnibus,lvfeng1130/omnibus,adamleff/omnibus,ashhher3/omnibus,sh9189/omnibus,sh9189/omnibus,Scalr/omnibus,ashhher3/omnibus,adamleff/omnibus,strangelittlemonkey/omnibus,Altiscale/omnibus,pskrz/omnibus,servebox/omnibus,rapid7/omnibus,higanworks/omnibus,DataDog/omnibus-ruby,Scalr/omnibus,chef/omnibus,szechyjs/omnibus,lvfeng1130/omnibus,3ofcoins/chef-omnibus,higanworks/omnibus,jamesn/omnibus,chef/omnibus,3ofcoins/chef-omnibus,intfrr/omnibus,Altiscale/omnibus,pskrz/omnibus,rhass/omnibus,rhass/omnibus,adamleff/omnibus,jamesn/omnibus,Altiscale/omnibus,hugosato/omnibus,hugosato/omnibus,pskrz/omnibus,ashhher3/omnibus,chef/omnibus,intfrr/omnibus,sh9189/omnibus,strangelittlemonkey/omnibus,DataDog/omnibus-ruby,rhass/omnibus,jamesn/omnibus,mattray/omnibus,szechyjs/omnibus,szechyjs/omnibus,strangelittlemonkey/omnibus,mattray/omnibus,servebox/omnibus,mattray/omnibus,lvfeng1130/omnibus,rapid7/omnibus,intfrr/omnibus,Scalr/omnibus,higanworks/omnibus,3ofcoins/chef-omnibus,rapid7/omnibus