substrate: allow run path to be relative
substrate: allow run path to be relative

mitchellh/vagrant-installers,chrisroberts/vagrant-installers,chrisroberts/vagrant-installers,mitchellh/vagrant-installers,redhat-developer-tooling/vagrant-installers,chrisroberts/vagrant-installers,chrisroberts/vagrant-installers,chrisroberts/vagrant-installers,mitchellh/vagrant-installers,redhat-developer-tooling/vagrant-installers,mitchellh/vagrant-installers,redhat-developer-tooling/vagrant-installers,chrisroberts/vagrant-installers,mitchellh/vagrant-installers,mitchellh/vagrant-installers,redhat-developer-tooling/vagrant-installers