Since requests does not [honor HTTPS_PROXY](https://github.com/rmccue/Requests/issues/218), we need to add support for it. Closes https://github.com/razorpay/razorpay-php-testapp/issues/9
Since requests does not honor HTTPS_PROXY, we need to add support for it.
Closes razorpay/razorpay-php-testapp#9