title: API Requester Error using Postmaster
body: <p>I am attempting to use: <a href="https://www.postmaster.io" rel="nofollow">https://www.postmaster.io</a> for all my biggest shipping needs on my website project. I downloaded the example php zip folder here: <a href="https://github.com/postmaster/postmaster-php" rel="nofollow">https://github.com/postmaster/postmaster-php</a> I am having the following errors along with the current code I have. </p>
  
  <p>Okay so first off, I have a form submitting to the processing page. This looks like the following: </p>
  
  <pre><code>&lt;form method="post" action="/config/templates/checkout.php"&gt; 
     &lt;input type="text" name="zip_code" id="zip_code" class="form-control" placeholder="Zip Code" /&gt;
     &lt;input type="submit" name="Submit1" value="Submit" /&gt;
  &lt;/form&gt;
  </code></pre>
  
  <p>And then my processing page looks like this: </p>
  
  <pre><code>if (isset($_POST['Submit1'])) 
  {
      require_once('../libraries/postMaster/Postmaster.php');
      Postmaster::setApiKey("/* API key */");
  
      $zip_code = $_POST['zip_code'];
  
      echo $zip_code;
  
      $result = Postmaster_Rates::get(array(
          "from_zip" =&gt; "67124",
          "to_zip" =&gt; $zip_code,
          "weight" =&gt; 1.5,
          "carrier" =&gt; "fedex",
      ));
  
      var_dump($result);
  }
  </code></pre>
  
  <p>It is getting to the point of <code>$result = Postmaster_Rates::get(array(...</code> of the code and throws the following error. I have a feeling something is not getting passed through like it should, although I couldn't find anything to support my thought. </p>
  
  <blockquote>
    <p>Fatal error: Uncaught exception 'InvalidData_Error' with message 'APIError 1000: Authentication Failed' in /home/www//config/libraries/postMaster/Postmaster/ApiRequestor.php:63<br>
    Stack trace:<br>
    #0 /home/www//config/libraries/postMaster/Postmaster/Rates.php(15): <code>Postmaster_ApiRequestor-&gt;request('post', '/v1/rates', Array)</code><br>
    #1 /home/www/config/templates/checkout.php(19): <code>Postmaster_Rates::get(Array)</code><br>
    #2 {main} thrown in /home/www//config/libraries/postMaster/Postmaster/ApiRequestor.php on line 63</p>
  </blockquote>
  
  <p>(<em>I removed my main url from the above error code.</em>)</p>
  
  <p>Anyone have any experience using this system that could help me out?</p>