Merge pull request #2395 from puppetlabs/pdksync_(MAINT)_Pin_puppetlabs-puppet_agent

pdksync - (CONT-768) Pin puppetlabs-puppet_agent

Author: jordanbreen28

.fixtures.yml

@@ -4,7 +4,9 @@ fixtures:
     facts: 'https://github.com/puppetlabs/puppetlabs-facts.git'
     portage: "https://github.com/gentoo/puppet-portage.git"
     provision: 'https://github.com/puppetlabs/provision.git'
-    puppet_agent: 'https://github.com/puppetlabs/puppetlabs-puppet_agent.git'
+    puppet_agent:
+      repo: 'https://github.com/puppetlabs/puppetlabs-puppet_agent.git'
+      ref: v4.12.1
     stdlib: "https://github.com/puppetlabs/puppetlabs-stdlib.git"
     yumrepo_core: 
       repo: "https://github.com/puppetlabs/puppetlabs-yumrepo_core.git"