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

code from pantheon

* code from pantheon

wp/wp-content/plugins/wordpress-seo/src/conditionals/migrations-conditional.php

@@ -0,0 +1,36 @@
+<?php
+
+namespace Yoast\WP\SEO\Conditionals;
+
+use Yoast\WP\SEO\Config\Migration_Status;
+
+/**
+ * Class for integrations that depend on having all migrations run.
+ */
+class Migrations_Conditional implements Conditional {
+
+	/**
+	 * The migration status.
+	 *
+	 * @var Migration_Status
+	 */
+	protected $migration_status;
+
+	/**
+	 * Migrations_Conditional constructor.
+	 *
+	 * @param Migration_Status $migration_status The migration status object.
+	 */
+	public function __construct( Migration_Status $migration_status ) {
+		$this->migration_status = $migration_status;
+	}
+
+	/**
+	 * Returns `true` when all database migrations have been run.
+	 *
+	 * @return bool `true` when all database migrations have been run.
+	 */
+	public function is_met() {
+		return $this->migration_status->is_version( 'free', \WPSEO_VERSION );
+	}
+}