Enable deploying code for the raspberry pis

Also, sets up a systemd service to start all the code.

Change-Id: If993426b36d0910497579ad86e330699f8a7d2e7
diff --git a/y2020/vision/rootfs/modify_rootfs.sh b/y2020/vision/rootfs/modify_rootfs.sh
index 239db0a..219590f 100755
--- a/y2020/vision/rootfs/modify_rootfs.sh
+++ b/y2020/vision/rootfs/modify_rootfs.sh
@@ -76,6 +76,7 @@
 sudo cp target_configure.sh "${PARTITION}/tmp/"
 sudo cp dhcpcd.conf "${PARTITION}/tmp/dhcpcd.conf"
 sudo cp change_hostname.sh "${PARTITION}/tmp/change_hostname.sh"
+sudo cp frc971.service "${PARTITION}/etc/systemd/system/frc971.service"
 
 target /bin/mkdir -p /home/pi/.ssh/
 cat ~/.ssh/id_rsa.pub | target tee /home/pi/.ssh/authorized_keys