Fix bug 1693: add prometheus authentication support

Change-Id: I82ef4c35deaf2d9a90a9a7e036da28c97026613a
Signed-off-by: David Garcia <david.garcia@canonical.com>
diff --git a/docker/Dockerfile b/docker/Dockerfile
index df0bb8d..bc6f94a 100644
--- a/docker/Dockerfile
+++ b/docker/Dockerfile
@@ -58,6 +58,8 @@
 ENV OSMMON_COLLECTOR_INTERVAL 30
 ENV OSMMON_EVALUATOR_INTERVAL 30
 ENV OSMMON_PROMETHEUS_URL http://prometheus:9090
+ENV OSMMON_PROMETHEUS_USER admin
+ENV OSMMON_PROMETHEUS_PASSWORD admin
 ENV OSMMON_GRAFANA_URL http://grafana:3000
 ENV OSMMON_GRAFANA_USER admin
 ENV OSMMON_GRAFANA_PASSWORD admin