'--remember*' options not working when the parent directory not exist

[BlacAmDK]

When the directory /var/cache/tuigreet does not exist, the following save files can not save correctly.

tuigreet/src/info.rs

Lines 17 to 19 in 599d8d5

	const LAST_USER_USERNAME: &str = "/var/cache/tuigreet/lastuser";
	const LAST_USER_NAME: &str = "/var/cache/tuigreet/lastuser-name";
	const LAST_SESSION: &str = "/var/cache/tuigreet/lastsession";