Don't overwrite jenkins user authorized keys

Our CI has a real jenkins user that needs to be able to SSH to nodes in
order to copy logs, so don't overwrite its authorized keys file. We can
still test everything else about the jenkinsuser class.

Change-Id: I766f9992359a19277eda94f59835a0c9263e540a

spec/acceptance/fixtures/master.pp

@@ -1,6 +1,4 @@
-class { '::jenkins::jenkinsuser':
-  ssh_key => 'sshkey',
-}
+class { '::jenkins::jenkinsuser': }
 
 class { '::jenkins::master':
   vhost_name              => '127.0.0.1',

spec/acceptance/fixtures/slave.pp

@@ -1,6 +1,5 @@
 class { '::jenkins::slave':
-  ssh_key => 'sshkey',
-  user    => true
+  user => true
 }
 
 class { '::jenkins::job_builder':