Hyper POST request always yields 400
<p>I am trying to send a POST request to a site using Hyper 0.9. The request works with <code>curl</code>:</p>

<pre class="lang-none prettyprint-override"><code>curl https://api.particle.io/v1/devices/secret/set_light -d args=0 -d access_token=secret
</code></pre>

<p>and Python:</p>

<pre class="lang-py prettyprint-override"><code>import requests
r = requests.post("https://api.particle.io/v1/devices/secret/set_light",
    data={"access_token": "secret", "args": "0"})
</code></pre>

<p>but my Rust implementation doesn't seem to go through, always yielding 400.</p>

<pre><code>use hyper::client::Client;

let addr = "https://api.particle.io/v1/devices/secret/set_light";
let body = "access_token=secret&amp;args=0";
let mut res = client.post(addr)
                .body(body)
                .send()
                .unwrap();
</code></pre>