Upgrade to daemonize 0.5.0 to get rid of boxfnonce

[dverbeir]

boxfnonce crate is obsolete since Rust 1.35 and cargo audit complains about it. daemonize 0.5.0 doesn't use it any longer but is incompatible with earlier version in that the exit_action() modifier is no longer supported.

Despite the lack of any hint as to how to achieve the same thing with the newer version, it seems it can be done using daemonize.execute() instead of damonize.start(), since it will allow the parent to continue execution past the fork point.

[kennytm]

this is a duplicate of #361.