susoapi 0.2.1

• Fix bug where some requests failed when the server URL had a terminal /.
• Allow the user to check credentials provided as arguments in check_credentials() rather than as entries in .Renviron. This allows checking credentials without setting them. The check_credentials() function still defaults to environment variable values if credentials not arguments not provided as function arguments.
• Update tests and test fixtures to Survey Solutions 24.06.1