rescue from Faraday errors and raise custom one

[Azdaroth]

It would be a good addition to rescue from Faraday errors (e.g. TimeoutError or could be more generic and catch all errors inheriting form Faraday::ClientError) and raise custom one - it would be cleaner and would provide better abstraction as currently it requires to know how Faraday works when using bookingsync-api and catching such exceptions.