Add `logrotated` config for `nomad` log files.

```
--- /dev/null
+++ b/cookbooks/nomad/files/etc/logrotate.d/nomad
@@ -0,0 +1,13 @@
+/var/log/nomad.log
+{
+        rotate 4
+        weekly
+        missingok
+        notifempty
+        compress
+        delaycompress
+        sharedscripts
+        postrotate
+                /usr/lib/rsyslog/rsyslog-rotate
+        endscript
+}
```

cookbooks/nomad/files/etc/logrotate.d/nomad

@@ -0,0 +1,13 @@
+/var/log/nomad.log
+{
+        rotate 4
+        weekly
+        missingok
+        notifempty
+        compress
+        delaycompress
+        sharedscripts
+        postrotate
+                /usr/lib/rsyslog/rsyslog-rotate
+        endscript
+}

cookbooks/nomad/setup.rb

@@ -103,3 +103,10 @@ end
 service 'rsyslog' do
   action [ :nothing ]
 end
+
+# Deploy the `logrotated` configuration:
+remote_file '/etc/logrotate.d/nomad' do
+  owner 'root'
+  group 'root'
+  mode '644'
+end