Release 8.6.4

Author: twilio-dx

src/Twilio/VersionInfo.php

@@ -7,7 +7,7 @@
 class VersionInfo {
     const MAJOR = "8";
     const MINOR = "6";
-    const PATCH = "3";
+    const PATCH = "4";
 
     public static function string() {
         return implode('.', array(self::MAJOR, self::MINOR, self::PATCH));