Require ssh_key, username, password and url

Default these values to '' does provide any real value. We should
force the user to setup something other then an empty string.

Change-Id: I04da6afae5d39a20f9601b0dbd834e97d280d028
Signed-off-by: Paul Belanger <pabelanger@redhat.com>

manifests/jenkinsuser.pp

@@ -1,7 +1,7 @@
 # == Class: jenkins::jenkinsuser
 #
 class jenkins::jenkinsuser(
-  $ssh_key = '',
+  $ssh_key,
   $ensure = present,
   $gitfullname = 'OpenStack Jenkins',
   $gitemail = 'jenkins@openstack.org',

manifests/job_builder.pp

@@ -1,9 +1,9 @@
 # == Class: jenkins::job_builder
 #
 class jenkins::job_builder (
-  $url = '',
-  $username = '',
-  $password = '',
+  $url,
+  $username,
+  $password,
   $git_revision = 'master',
   $git_url = 'https://git.openstack.org/openstack-infra/jenkins-job-builder',
   $config_dir = '',

manifests/slave.pp

@@ -1,7 +1,7 @@
 # == Class: jenkins::slave
 #
 class jenkins::slave(
-  $ssh_key = '',
+  $ssh_key,
   $user = true,
   $gitfullname = 'OpenStack Jenkins',
   $gitemail = 'jenkins@openstack.org',