title: apollo-client does not work with CORS
body: <p>I am writing a graphql server component on AWS Lambda (NOT using graphql-server).  On the client side I'm using apollo-client.  On the response of the lambda function I'm setting </p>
  
  <pre><code>const response = {
      statusCode: 200,
      headers: {
          "Access-Control-Allow-Origin": "*" // Required for CORS support to work
      },
      body: JSON.stringify({
          result: 'mock data',
          input: event,
      }),
  };
  callback(null, response);
  </code></pre>
  
  <p>On the client side using ApolloClient I get the following error </p>
  
  <p><strong>Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin '<a href="http://localhost:8080" rel="noreferrer">http://localhost:8080</a>' is therefore not allowed access.</strong></p>
  
  <p>However when I execute the same request using something like axios then it works fine.  Furthermore when I just execute the request over something like postman I see the "Access-Control-Allow-Origin" setting enabled on the response.  Is this a known issue with apollo-client and how do I fix this?</p>