Bump directories

From Changelog:
> BREAKING CHANGE The behavior of executable_dir has been
> adjusted to not depend on $XDG_DATA_HOME. Code, which
> assumed that setting the $XDG_DATA_HOME environment
>variable also impacted executable_dir if the $XDG_BIN_HOME
> environment variable was not set, requires adjustment.

We do not appear to use the executable_dir() function, so this
breaking change should not affect us.

Signed-off-by: Jonathan Schwender <[email protected]>

Author: jschwe

Cargo.lock

@@ -34,7 +34,7 @@ bytes = "1"
 chrono = { version = "0.4", optional = true }
 clap = "2.23.0"
 counted-array = "0.1"
-directories = "3"
+directories = "4.0.1"
 env_logger = "0.9"
 filetime = "0.2"
 flate2 = { version = "1.0", optional = true, default-features = false, features = ["rust_backend"] }