Add declare(strict_types=1); to PHP instead of ticks (#496)

Author: zonuexe

snippets/php-mode/strict-types

@@ -0,0 +1,7 @@
+-# -*- mode: snippet -*-
+-# contributor: USAMI Kenta <[email protected]>
+-# name: declare(strict_types=1)
+-# key: strict_types
+-# group: definitions
+-# --
+declare(strict_types=1);