Improve info messages during RPM creation
Improve info messages during RPM creation

* Add `info` message when RPM signing is enabled
* Print ‘creation’ message right before package creation

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