title: base_uri not being based from guzzle client instantiation
body: <p>I'm using lumen trying to set up simple api requests via guzzle.</p>
  
  <p>The problem is the base_uri parameter doesn't appear to be passed correctly on the initial <code>new Client()</code>. </p>
  
  <p>Simplified example:</p>
  
  <pre><code>use GuzzleHttp\Client;
  
  $client = new Client([
      'base_uri' =&gt; 'https://siteurl.com/api/v2'
  ]);
  </code></pre>
  
  <p>Then calling the api via get</p>
  
  <pre><code>$res = $client-&gt;get('orders', [
      'query' =&gt; [
          'status' =&gt; 'completed'
      ]
  ]);
  </code></pre>
  
  <p>does not work. I've been careful not to use absolute urls like <code>/orders</code>. If I bypass base_uri entirely and just add it on the get method <code>$client-&gt;get('https://siteurl.com/api/v2/orders')</code>, it works.</p>
  
  <p>I'm using: 
  "laravel/lumen-framework": "5.0.*",
  "guzzlehttp/guzzle": "^6.0"</p>
  
  <p><strong>*Follow-up:</strong></p>
  
  <p>I added the debug flag so I could compare the headers, and the noticable difference is in the get request line.</p>
  
  <p>Absolute url in the get method (bypassing base_uri):</p>
  
  <blockquote>
    <p>GET /api/v2/orders?status=completed HTTP/1.1</p>
  </blockquote>
  
  <p>Using base_uri (version is being stripped):</p>
  
  <blockquote>
    <p>GET /api/orders?status=completed HTTP/1.1</p>
  </blockquote>