Paddle Billing Client Tokens & docs tweaks

[deanpcmad]

Paddle have recently added client side tokens as a way to interact with the Paddle API using Paddle.js without exposing your API tokens. Paddle recommend using these instead of passing the seller option, as new features may require it.

The latest feature of Paddle.js is the ability to generate localised price previews on the fly, which is great for building pricing pages as it shows the customer's local currency (with taxes too). This was a feature I've been requesting since the start as the previous version had it too.

This PR adds client_token to PaddleBilling, which is set by environment variables or in the credentials/secrets files.

I've also updated the Paddle Billing subscription docs and renamed some Pay::Paddle examples to Pay::PaddleClassic

[excid3]

I missed the client side token change. Good to know! 👍

Thanks for these!

[excid3]

I assume we should remove the seller_id too while we're here then since we haven't released this?

Looks like it:

Existing methods that use seller will continue to work, but future methods may require client-side tokens. We recommend that you replace the seller parameter with token and a client-side token when you're next reviewing your code.

[deanpcmad]

Ah nice, was just about to do that but I can see you've already done it 😅