Trickster with influxdb prometheus endpoint needs post_uri #272

There needs to be a post_uri addon unless i mis-understand how this functions.

The schema for using the influxdb URL build into influxdb is:

http://myinflux.server.com:8086/api/v1/prom/read?db=somedatabase&u=someuser&p=somepassword

The only way i could do this was using nginx.