Handle basic auth using the syntax appropiate to the Faraday version

[cbeer]

Addresses some deprecation warnings in Faraday 1.x, and makes requests with basic auth work with Faraday 2.x:

WARNING: `Faraday::Connection#basic_auth` is deprecated; it will be removed in version 2.0.
While initializing your connection, use `#request(:basic_auth, ...)` instead.
See https://lostisland.github.io/faraday/middleware/authentication for more usage info.