(MODULES-7852) - Fix Puppet 6 related failures

Author: eimlav

.fixtures.yml

@@ -4,5 +4,11 @@ fixtures:
     stdlib: "https://github.com/puppetlabs/puppetlabs-stdlib.git"
     firewall: "https://github.com/puppetlabs/puppetlabs-firewall.git"
     concat: "https://github.com/puppetlabs/puppetlabs-concat.git"
+    yumrepo_core: 
+      repo: "https://github.com/puppetlabs/puppetlabs-yumrepo_core.git"
+      puppet_version: ">= 6.0.0"
+    augeas_core: 
+      repo: "https://github.com/puppetlabs/puppetlabs-augeas_core.git"
+      puppet_version: ">= 6.0.0"
   symlinks:
     postgresql: "#{source_dir}"

manifests/server/grant.pp

@@ -2,7 +2,7 @@
 define postgresql::server::grant (
   String $role,
   String $db,
-  Optional[String] $privilege      = undef,
+  String $privilege      = '',
   Pattern[#/(?i:^COLUMN$)/,
     /(?i:^ALL SEQUENCES IN SCHEMA$)/,
     /(?i:^ALL TABLES IN SCHEMA$)/,