Automatically load Grafana Autometrics dashboards

[brettimus]

Once #3 is merged, it will still be necessary to manually import the grafana dashboards for autometrics. I would like to find a way to do this automatically, however right now it's not possible because the JSON files require that the user selects a prometheus datasource upon importing. Not sure if there's a way around this.

[brettimus]

likely solution: update the JSON files to not require an input for the prometheus datasource. just use the default prometheus datasource