title: response.body is "" even though webmock .to_return(:body => "return") is set
body: <p>I'm writing unit tests for a Rails service using minitest. A snippet of my test looks like this:</p>
  
  <pre><code>stub_request(:get, @service_url)
          .with(:headers =&gt; @authheader)
          .to_return(:body =&gt; "ABC", :status =&gt; 200)
  get :index
  </code></pre>
  
  <p>After the get :index, response.code is 200 as expected (and I've changed it to 201 in the .to_return and seen that code be correct after get :index, but every time response.body is "". I'm sure I'm just doing something unimaginably dumb here and welcome being told what a dummy I am. :)</p>
  
  <p>Thanks in advance</p>
  
  <p>minitest 5.8.2
  webmock 3.0.1
  rails 4</p>