Add /bin to PATH for CRL cronjob

Checking the root's mail (/var/mail/root) I finally saw the root cause
of the CRL cronjob not working.

/bin/sh: curl: command not found

now, curl, (and most commands used by that cronjob) is in the /bin bash,
so we need to add it to the environment's PATH for the cronjob.

Change-Id: If10855b801782eeaf2006cd57071d74d13daf8c2
Closes-Bug: #1712404

manifests/certmonger/ca/crl.pp

@@ -138,7 +138,7 @@ class tripleo::certmonger::ca::crl (
   cron { 'tripleo-refresh-crl-file':
     ensure      => $ensure,
     command     => $cron_cmd,
-    environment => 'PATH=/usr/bin SHELL=/bin/sh',
+    environment => 'PATH=/usr/bin:/bin SHELL=/bin/sh',
     user        => 'root',
     minute      => $minute,
     hour        => $hour,