title: how to make post request using tesla in elixir
body: <p>I'm trying to make post request using tesla but getting error:</p>
  
  <pre><code>(CaseClauseError) no case clause matching: %{name: "ecdebit"}
  (hackney) /deps/hackney/src/hackney_request.erl:312::hackney_request.handle_body/4
  (hackney) /deps/hackney/src/hackney_request.erl:81::hackney_request.perform/2
  (hackney) /deps/hackney/src/hackney.erl:372::hackney.send_request/2
  (tesla) lib/tesla/adapter/hackney.ex:69: Tesla.Adapter.Hackney.request/5
  (tesla) lib/tesla/adapter/hackney.ex:31: Tesla.Adapter.Hackney.call/2
  </code></pre>
  
  <p>my request code is</p>
  
  <pre><code>request_body = %{
    name: "ecdebit",
  }
  Tesla.post(client, "/contactdb/lists", request_body)
  </code></pre>
  
  <p>in tesla base url is: <code>https://api.sendgrid.com/v3</code> and also set authorization <code>key</code>. how can we pass data for post request ?</p>
  
  <p>as in tesla documentation define post request as this:</p>
  
  <pre><code>Tesla.post("http://httpbin.org/post", "data", headers: [{"content-type", "application/json"}])
  </code></pre>
  
  <p>Is there any in this planet who could help to get rid of this glitch :(. </p>