systemd backport for Debian/jessie

apt-get update && apt-get -y install apt-transport-https
echo 'deb https://people.debian.org/~mika/systemd/jessie/ ./' > /etc/apt/sources.list.d/systemd_backport.list
wget -O /etc/apt/preferences.d/systemd_backport https://people.debian.org/~mika/systemd/jessie/apt_preferences_systemd_backport
wget -O /etc/apt/trusted.gpg.d/mika.gpg https://people.debian.org/~mika/systemd/jessie/apt_key.gpg
apt-get update
apt-get install systemd