Fix issue when decoding the Current Customer JWT Payload
Fix issue when decoding the Current Customer JWT Payload

The token created from this endpoint uses algorithm "HS512". Added this algorithm to the array.
https://developer.bigcommerce.com/api-docs/storefront/current-customer-api

Also noticed that when using `verify_payload` it gave an error since there were three values returned. Put a `__` to handle the last value returned.
bigcommerce/bigcommerce-api-python