[AL-950] Added fatal exit code to grunt release task
[AL-950] Added fatal exit code to grunt release task

uhef/Oskari-Routing-frontend,uhef/Oskari-Routing-frontend,uhef/Oskari-Routing-frontend,uhef/Oskari-Routing-frontend,uhef/Oskari-Routing-frontend,uhef/Oskari-Routing-frontend