Added grafana to the proxy solution. It's now available at
http://localhost/grafana.

Change-Id: I70cad6b3484f4d997632280da3858659a670d470
diff --git a/nginx_config/nginx-upstreams.ctmpl b/nginx_config/nginx-upstreams.ctmpl
index 188aa10..747e36b 100644
--- a/nginx_config/nginx-upstreams.ctmpl
+++ b/nginx_config/nginx-upstreams.ctmpl
@@ -1,3 +1,8 @@
+upstream api-grafana {
+    {{range service "grafana-web-ui" "any"}}
+    server {{.Address}}:{{.Port}};
+    {{end}}
+}
 upstream api-docker {
     {{range service "portainer" "any"}}
     server {{.Address}}:{{.Port}};