title: webpack dev server CORS issue
body: <p>I am using <code>webpack-dev-server v1.10.1</code> to boost up my Redux project and I have the options below:</p>
  
  <pre><code>contentBase: `http://${config.HOST}:${config.PORT}`,
  quiet: false,
  noInfo: true,
  hot: true,
  inline: true,
  lazy: false,
  publicPath: configWebpack.output.publicPath,
  headers: {"Access-Control-Allow-Origin": "*"},
  stats: {colors: true}
  </code></pre>
  
  <p>In the JS, I am using <code>request</code> from <code>superagent</code> to generate a HTTP GET call</p>
  
  <pre><code>request
            .get(config.APIHost + apiUrl)
            .set('Accept', 'application/json')
            .withCredentials()
            .end(function (err, res) {
                  if (!err &amp;&amp; res.body) {
                      disptach(() =&gt; {
                          return {
                              type: actionType || GET_DATA,
                              payload: {
                                  response: res.body
                              }
                          }
                      });
                  }
            });
  </code></pre>
  
  <p>But I got the CORS error:</p>
  
  <pre><code>XMLHttpRequest cannot load http://localhost:8000/api/getContentByType?category=all. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://localhost:5050' is therefore not allowed access
  </code></pre>
  
  <p>Any suggestion to resolve this? Thanks a lot</p>