Merge pull request #307 from puppetlabs/CONT-791-add_puppet8_support

(CONT-791) - Add Puppet 8/Drop Puppet 6

Author: LukasAud

.devcontainer/devcontainer.json

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

.fixtures.yml

@@ -4,7 +4,7 @@ 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:
     package: "#{source_dir}"