Gauge with 4 color zone instead of default 3

[hotNipi]

Here is an example

[Announce] Dashboard Version 2.18.0

Just pushed latest updates to dashboard... mainly a cleanup of small issues - but includes updating to the now maintained justgage library, so we no longer have to monkeypatch old bugs in that library, and also moving the build to gulp4 in order to support Nodejs 12. Enhancements Update justgauge to latest (now maintained) version and drop monkeypatch. Issue #535. Add engines node8 to package.json (we only support node8 anyway so should have made this mandatory) Fixes Stop propagation of s…