Establish postgres version

Author: LukasAud

.github/workflows/integration_test.yml

@@ -83,6 +83,7 @@ jobs:
         # Redact password
         FILE='spec/fixtures/litmus_inventory.yaml'
         sed -e 's/password: .*/password: "[redacted]"/' < $FILE || true
+        sed -i '/vars:/a \ \ puppet_enterprise::params::postgres_version: "13"' "$FILE"
 
     - name: Install PE
       run: |