Upgrade Grafana to V5.2.2

[thomas-hutterer-tik]

I am missing the Postgres support in the installed version. Therefor an upgrade to the current Grafana version would be highly welcome. Or some hints how I could do the upgrade myself might also do. Many Thanks Thomas

[Choromanski]

I to am missing this option, would be nice to have

[scottrpoulin]

@thomas-hutterer-tik and @Choromanski I updated the grafana to 6.3.5 (Latest) Should be working https://github.com/scottrpoulin/heroku-grafana-6.3.5

I tried to make it very similar if not the same to eliperelman's repo.