This adds ldap support to the grafana chart. This required updating
the version of Grafana to 5.0, as this version allows for using
configuration files to bootstrap the datasources and dashboards
instead of using the grafana http api. This was a necessary change
as using ldap for grafana presented issues trying to create the
datasource via the http api
This also adds a basic helm test for grafana. This test simply
verifies whether the prometheus datasource configured exists and
whether the number of dashboards reported by the admin api matches
the number of dashboards expected
Change-Id: I2e987cb425adba9f909722ffdb25b83f82710c4d
e081c19fe8