Adding PATH necessary to find the attic binary.

sample/atticmatic.cron

@@ -1,3 +1,3 @@
 # You can drop this file into /etc/cron.d/ to run atticmatic nightly.
 
-0 3 * * * root /usr/local/bin/atticmatic
+0 3 * * * root PATH=$PATH:/usr/local/bin /usr/local/bin/atticmatic