Merge pull request #211 from puppetlabs/CONT-778-add_puppet8_support

(Cont 778) -  add puppet 8 support/drop puppet 6 support

Author: GSPatton

.devcontainer/devcontainer.json

@@ -5,7 +5,7 @@
 	"settings": {
 		"terminal.integrated.profiles.linux": {
 			"bash": {
-				"path": "bash",
+				"path": "bash"
 			}
 		}
 	},

.fixtures.yml

@@ -5,6 +5,6 @@ fixtures:
     provision: 'https://github.com/puppetlabs/provision.git'
     puppet_agent:
       repo: 'https://github.com/puppetlabs/puppetlabs-puppet_agent.git'
-      ref: v4.12.1
+      ref: v4.13.0
   symlinks:
     "facter_task": "#{source_dir}"