Merged in feature/from-pantheon (pull request #16)

code from pantheon

* code from pantheon

wp/wp-content/plugins/wordpress-seo-premium/src/integrations/upgrade-integration.php

@@ -0,0 +1,34 @@
+<?php
+
+namespace Yoast\WP\SEO\Premium\Integrations;
+
+use WPSEO_Upgrade_Manager;
+use Yoast\WP\SEO\Conditionals\No_Conditionals;
+use Yoast\WP\SEO\Integrations\Integration_Interface;
+
+/**
+ * Class Upgrade_Integration.
+ */
+class Upgrade_Integration implements Integration_Interface {
+
+	use No_Conditionals;
+
+	/**
+	 * Initializes the integration.
+	 *
+	 * This is the place to register hooks and filters.
+	 *
+	 * @return void
+	 */
+	public function register_hooks() {
+		\add_action( 'init', [ $this, 'run_upgrade' ], 11 );
+	}
+
+	/**
+	 * Run the upgrade for Yoast SEO Premium.
+	 */
+	public function run_upgrade() {
+		$upgrade_manager = new WPSEO_Upgrade_Manager();
+		$upgrade_manager->run_upgrade( \WPSEO_PREMIUM_VERSION );
+	}
+}