plug 0.2.0

Bug fixes

plug_execute_query() now replaces placeholders in the SQL template. The previous implementation failed for any template with placeholders, and exposed internal variables of the function to the template.
plug_execute_query() and plug_download_base() now stop with a clear message when no valid token is available, instead of sending an unauthenticated request.
plug_store_credentials() discards the cached token, so new credentials are used right away.
plug_get_valid_token() reports the actual reason of a failure (missing credentials, network problem or response of the ‘API’) instead of always showing “No valid credentials found.”.
The example of plug_store_credentials() no longer overwrites credentials stored in the system keyring.
The package now declares its dependency on R >= 4.1.0.

New plug_clear_credentials() removes the stored credentials and tokens.
plug_execute_query() supports the placeholders {x}, {x*}, {`x`} and {I(x)}, with values quoted according to Microsoft SQL Server syntax.
plug_execute_query() and plug_download_base() gain the argument auth_endpoint, and request a new token when the cached one is rejected by the ‘API’.
plug_get_valid_token() gains the argument force.
Errors of the ‘API’ now include the message returned by the server.
plug_download_base() validates the name of the base.