Add python3 option to jenkins::slave.

Adds a new python3 option to our jenkins slave manifest which
can be used to enable using python3-pip when installing
*key* pip packages for unit testing (tox, setuptools-git).

Also, updates openstack_project::slave so that it supports the option
as well.

Change-Id: I5face30b09e3e8d2f70b4da83481f4f8bd33fc51
Reviewed-on: https://review.openstack.org/32452
Reviewed-by: James E. Blair <corvus@inaugust.com>
Reviewed-by: Clark Boylan <clark.boylan@gmail.com>
Reviewed-by: Elizabeth Krumbach Joseph <lyz@princessleia.com>
Approved: Clark Boylan <clark.boylan@gmail.com>
Tested-by: Jenkins

modules/jenkins/manifests/slave.pp

@@ -5,6 +5,7 @@ class jenkins::slave(
   $sudo = false,
   $bare = false,
   $user = true,
+  $python3 = false,
 ) {
 
   include pip
@@ -132,11 +133,20 @@ class jenkins::slave(
     'tox',
   ]
 
+  if $python3 {
+    include pip::python3
+    package { $pip_packages:
+      ensure   => latest,  # we want the latest from these
+      provider => pip3,
+      require  => Class[pip::python3],
+    }
+  } else {
     package { $pip_packages:
       ensure   => latest,  # we want the latest from these
       provider => pip,
       require  => Class[pip],
     }
+  }
 
   package { 'python-subunit':
     ensure   => absent,

modules/openstack_project/manifests/slave.pp

@@ -4,7 +4,8 @@ class openstack_project::slave (
   $bare = false,
   $certname = $::fqdn,
   $ssh_key = '',
-  $sysadmins = []
+  $sysadmins = [],
+  $python3 = false
 ) {
   include openstack_project
   include openstack_project::tmpcleanup
@@ -17,6 +18,7 @@ class openstack_project::slave (
   class { 'jenkins::slave':
     bare    => $bare,
     ssh_key => $ssh_key,
+    python3 => $python3,
   }
   class { 'salt':
     salt_master => 'ci-puppetmaster.openstack.org',