Grafana dashboard

Trying this out - but nothing shows up in the grafana dashboard

Is it still working?

```
e.Use(echoprometheus.NewMetric())
e.GET("/metrics", echo.WrapHandler(promhttp.Handler()))
```

http://localhost:1323/metrics does show

```
# HELP echo_http_request_duration_seconds HTTP request latencies in seconds.
# TYPE echo_http_request_duration_seconds summary
echo_http_request_duration_seconds_sum{host="localhost:1323",method="GET",url="/metrics"} 0.012348164
echo_http_request_duration_seconds_count{host="localhost:1323",method="GET",url="/metrics"} 18
echo_http_request_duration_seconds_sum{host="localhost:1323",method="GET",url="/ping"} 0.0030877769999999986
echo_http_request_duration_seconds_count{host="localhost:1323",method="GET",url="/ping"} 355
```

but the grafana dashboard is blank