Made the ASANA.api_key initialized from an argument in the creation procedure.
Removed ASANA_SINGLETON since the ASANA object has to be initialized with a valid API key.
Made ASANA.last_error detachable, and added is_success (an alternative would be to rename last_error as last_operation_status, and rename the class, but it seems weird to have last_error.is_success )
Updated .ecf file, to be a library, and added a specific "test_.." target.