Apply workaround for bug in versions of PHP < 5.3.9.

This change is needed to address a bug in older versions of PHP 5.3
affecting inheritance (see https://bugs.php.net/bug.php?id=66818).

CHANGELOG.md

@@ -1,3 +1,10 @@
+v1.0.1 (2014-xx-xx)
+================================================================================
+
+- __FIX__: applied a minor workaround for a bug in old versions of PHP < 5.3.9
+  affecting inheritance.
+
+
 v1.0.0 (2014-08-01)
 ================================================================================
 

src/Cluster/ClusterStrategy.php

@@ -346,11 +346,6 @@ public function getSlot(CommandInterface $command)
         return $slot;
     }
 
-    /**
-     * {@inheritdoc}
-     */
-    abstract public function getSlotByKey($key);
-
     /**
      * Checks if the specified array of keys will generate the same hash.
      *
@@ -397,9 +392,4 @@ protected function extractKeyTag($key)
 
         return $key;
     }
-
-    /**
-     * {@inheritdoc}
-     */
-    abstract public function getDistributor();
 }