Enable influxDB storage backend for Grafana

You use InfluxDB Grafana to store dashboards.
grafanaDB: true marks it for use as dashboard storage (applicable for
InfluxDB & Elasticsearch)
Merge branch 'master' of github.com:echocat/puppet-grafana
Fixed missing commas that would break config.js
Merge pull request #3 from meson10/master

Fixed missing commas that would break config.js