Expose error details in "UnexpectedException" in Python library

[charlie-zhang109]

General information

• SDK/Library version:4.28.0
• Environment: Production

Issue description

When our backend tried to create a customer on BT side, we got the following UnexpectedError without a detailed message.

raise UnexpectedError("Unexpected HTTP_RESPONSE " + str(status))
braintree.exceptions.unexpected_error.UnexpectedError: Unexpected HTTP_RESPONSE 400

From this BT doc, looks like the client library needs to handle it.

Also Java library had this similar issue and it got fixed.

It would be helpful if that error was bubbled up to the exception, or generated a more specific exception like the Java library.

[charlie-zhang109]

Could someone take a look? It prevents our customer adding their credit cards so we're losing revenue. Thanks!