Dimitar Andreev

Fix headers; Small improvements; Add integration tests;

3

The key should be `headers`, otherwise there is an exception `Invalid lambda response received: Invalid API Gateway Response Keys: {'header'}`.

Init gapi

8

Made the changes from https://github.com/kennetpostigo/react-google-login-component/pull/5 and some minor tweaks. I'm wondering if all the options from https://developers.google.com/identity/sign-in/web/reference#gapiauth2clientconfig should be added as props? Maybe add `defaultProps` and `propTypes`? @kennetpostigo @darrenchiu what...