Add ping command to image

src/freedombone-image-customise

@@ -337,7 +337,7 @@ fi
 
 chroot "$rootdir" apt-get install -y sudo git dialog toilet build-essential openssh-server
 chroot "$rootdir" apt-get install -y avahi-daemon avahi-utils avahi-discover avahi-autoipd
-chroot "$rootdir" apt-get install -y iptables dnsutils net-tools network-manager
+chroot "$rootdir" apt-get install -y iptables dnsutils net-tools network-manager iputils-ping
 chroot "$rootdir" apt-get install -y libnss-mdns libnss-myhostname libnss-gw-name
 
 chroot "$rootdir" /bin/bash -x <<EOF