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

code from pantheon

* code from pantheon

wp/wp-content/plugins/wordpress-seo/lib/migrations/constants.php

@@ -0,0 +1,22 @@
+<?php
+
+namespace Yoast\WP\Lib\Migrations;
+
+/**
+ * Yoast migrations constants class.
+ */
+class Constants {
+
+	const MYSQL_MAX_IDENTIFIER_LENGTH = 64;
+	const SQL_UNKNOWN_QUERY_TYPE      = 1;
+	const SQL_SELECT                  = 2;
+	const SQL_INSERT                  = 4;
+	const SQL_UPDATE                  = 8;
+	const SQL_DELETE                  = 16;
+	const SQL_ALTER                   = 32;
+	const SQL_DROP                    = 64;
+	const SQL_CREATE                  = 128;
+	const SQL_SHOW                    = 256;
+	const SQL_RENAME                  = 512;
+	const SQL_SET                     = 1024;
+}