Added missing error class imports

Osukaru · Osukaru · commit 2258de4b6b2a · 2016-11-30T09:59:29.000+01:00
diff --git a/src/Queue.php b/src/Queue.php
@@ -1,6 +1,7 @@
 <?php
 namespace Ds;
 
+use Error;
 use OutOfBoundsException;
 
 /**
diff --git a/src/Stack.php b/src/Stack.php
@@ -1,6 +1,7 @@
 <?php
 namespace Ds;
 
+use Error;
 use OutOfBoundsException;
 
 /**
