update(travis): only build on master branch and PRs
update(travis): only build on master branch and PRs

pwistbac/material,hayloft/material,oostmeijer/material,daniel-nagy/material,marekmicek/material,david-gang/material,marekmicek/material,SamDLT/material,david-gang/material,bluebirdtech/material,Splaktar/material,ServiceManagementGroup/material,daniel-nagy/material,marekmicek/material,bluebirdtech/material,ServiceManagementGroup/material,bluebirdtech/material,Splaktar/material,bluebirdtech/material,SamDLT/material,crisbeto/material,DevVersion/material,miguelcobain/material,oostmeijer/material,profoundry-us/material,hayloft/material,pwistbac/material,ServiceManagementGroup/material,SamDLT/material,imjoeco/material,Splaktar/material,oostmeijer/material,profoundry-us/material,ilovett/material,miguelcobain/material,hayloft/material,ilovett/material,vertazzar/material,Splaktar/material,Frank3K/material,oostmeijer/material,DevVersion/material,crisbeto/material,profoundry-us/material,pwistbac/material,Frank3K/material,david-gang/material,crisbeto/material,clshortfuse/material,Frank3K/material,Frank3K/material,DevVersion/material,vertazzar/material,profoundry-us/material,hayloft/material,clshortfuse/material,imjoeco/material,daniel-nagy/material,miguelcobain/material,clshortfuse/material,miguelcobain/material,daniel-nagy/material,david-gang/material,graingert/material,crisbeto/material,imjoeco/material,vertazzar/material,ServiceManagementGroup/material,ilovett/material,pwistbac/material,angular/material,graingert/material,angular/material,angular/material,SamDLT/material,ilovett/material,graingert/material,clshortfuse/material,imjoeco/material,DevVersion/material,marekmicek/material,graingert/material,vertazzar/material,angular/material