Added nightly building to Travis
Added nightly building to Travis

Let's us check PHP 7 compatibility
pellaeon/Cachet,NossaJureg/Cachet,MatheusRV/Cachet-Sandstorm,ephillipe/Cachet,ematthews/Cachet,SamuelMoraesF/Cachet,eduardocruz/Cachet,coupej/Cachet,bthiago/Cachet,chaseconey/Cachet,withings-sas/Cachet,Surventrix/Cachet,alobintechnologies/Cachet,elektropay/Cachet,clbn/Cachet,displayn/Cachet,Mebus/Cachet,karaktaka/Cachet,robglas/Cachet,ZengineChris/Cachet,MatheusRV/Cachet-Sandstorm,n0mer/Cachet,whealmedia/Cachet,brianjking/openshift-cachet,chaseconey/Cachet,g-forks/Cachet,karaktaka/Cachet,nxtreaming/Cachet,murendie/Cachet,n0mer/Cachet,displayn/Cachet,withings-sas/Cachet,bthiago/Cachet,katzien/Cachet,pellaeon/Cachet,chaseconey/Cachet,ephillipe/Cachet,gm-ah/Cachet,MatheusRV/Cachet-Sandstorm,nxtreaming/Cachet,rogerapras/Cachet,alobintechnologies/Cachet,billmn/Cachet,anujaprasad/Hihat,SamuelMoraesF/Cachet,brianjking/openshift-cachet,Mebus/Cachet,rogerapras/Cachet,leegeng/Cachet,coupej/Cachet,ematthews/Cachet,leegeng/Cachet,murendie/Cachet,elektropay/Cachet,MatheusRV/Cachet-Sandstorm,sapk/Cachet,eduardocruz/Cachet,whealmedia/Cachet,g-forks/Cachet,eduardocruz/Cachet,wakermahmud/Cachet,withings-sas/Cachet,MatheusRV/Cachet-Sandstorm,wakermahmud/Cachet,elektropay/Cachet,0x73/Cachet,billmn/Cachet,h3zjp/Cachet,h3zjp/Cachet,billmn/Cachet,anujaprasad/Hihat,ematthews/Cachet,h3zjp/Cachet,wngravette/Cachet,robglas/Cachet,g-forks/Cachet,wngravette/Cachet,Mebus/Cachet,ZengineChris/Cachet,pellaeon/Cachet,cachethq/Cachet,ZengineChris/Cachet,murendie/Cachet,katzien/Cachet,gm-ah/Cachet,MicroWorldwide/Cachet,coupej/Cachet,karaktaka/Cachet,brianjking/openshift-cachet,rogerapras/Cachet,clbn/Cachet,everpay/Cachet,ephillipe/Cachet,sapk/Cachet,n0mer/Cachet,NossaJureg/Cachet,bthiago/Cachet,NossaJureg/Cachet,CloudA/Cachet,cachethq/Cachet,anujaprasad/Hihat,0x73/Cachet,everpay/Cachet,Surventrix/Cachet,MicroWorldwide/Cachet,sapk/Cachet,SamuelMoraesF/Cachet,wakermahmud/Cachet,CloudA/Cachet