Upgrade build-container image (#20438)
Upgrade build-container image (#20438)

* grafana/build-container: Upgrade to Ubuntu 18.04 base image
* grafana/build-container: Upgrade to Go 1.13.4
* grafana/build-container: Upgrade to Node 10.17.0
grafana/grafana,grafana/grafana,grafana/grafana,grafana/grafana,grafana/grafana,grafana/grafana,grafana/grafana