Add CORS headers for netlify function, and a script to run funtions locally

Author: gauravchl

package.json

@@ -18,6 +18,7 @@
   },
   "scripts": {
     "start": "react-scripts start",
+    "start:lambda": "netlify-lambda serve src/lambda",
     "build": "run-p build:**",
     "build:lambda": "netlify-lambda build src/lambda",
     "build:app": "react-scripts build",

src/lambda/graphql.js

@@ -5,5 +5,9 @@ exports.handler = async (request, context) => {
   await setup.run();
   const response = await handleRequest(request, context);
 
+  response.headers = {
+    'Access-Control-Allow-Origin': '*',
+    'Access-Control-Allow-Headers': 'Origin, X-Requested-With, Content-Type, Accept'
+  }
   return response;
 };