deploy using https://github.com/mislav/git-deploy

```
sudo gem install git-deploy
git remote add production scabot@scabot:/home/scabot/scabot
git deploy setup -r "production"
```

I think this may be needed: `ssh scabot 'cd /home/scabot/scabot && git checkout master'`.

`runit` etc is configured for scabot using
adriaanm/scala-jenkins-infra@a326d52

From now on, push changes to production using `git push production master`.

deploy/after_push

@@ -0,0 +1,17 @@
+#!/usr/bin/env bash
+set -e
+oldrev=$1
+newrev=$2
+
+run() {
+  [ -x $1 ] && $1 $oldrev $newrev
+}
+
+echo files changed: $(git diff $oldrev $newrev --diff-filter=ACDMR --name-only | wc -l)
+
+umask 002
+
+git submodule sync && git submodule update --init --recursive
+
+run deploy/before_restart
+run deploy/restart && run deploy/after_restart

deploy/before_restart

@@ -0,0 +1,8 @@
+#!/usr/bin/env ruby
+oldrev, newrev = ARGV
+
+def run(cmd)
+  exit($?.exitstatus) unless system "umask 002 && #{cmd}"
+end
+
+run "sbt stage"

deploy/restart

@@ -0,0 +1,3 @@
+#!/bin/sh
+
+killall -1 java ||: # only java process run by scabot -- will be restarted by runit