Riemann reporter doesn't appear to work

I use 2.7.0 version, the `lein install` doesn't appear to do anything or takes ages when I cloned this repository.

Mainly I see this in the logs:

```
2016-06-21 12:06:58,449 DEBUG (metrics-riemann-reporter-thread-1) [com.codahale.metrics.riemann.RiemannReporter] - Reporting metrics: for 1466503618 at 1466503618449
```

only once, and I can't see the data in Riemann.

Riemann appear to works as I tried to add metrics manually. I don't have any hint on how to make it works.

I use call this function at start time:

```
(defn init! []
(let [host "127.0.0.1"
port 5555
riemann-client (riemann/make-riemann host port)
riemann-reporter (riemann/reporter riemann-client
{:rate-unit TimeUnit/SECONDS
:duration-unit TimeUnit/MILLISECONDS
:filter MetricFilter/ALL})]
(log/debug (str "connecting to Riemann: " host ":" port))
(riemann/start riemann-reporter 1)))
```