Fixed tests for delete, has and fixed the cache clear proxy implementation.

Author: ndobromirov

PrefixedSimpleCache.php

@@ -44,7 +44,7 @@ public function __construct(CacheInterface $simpleCache, $prefix)
      */
     public function clear()
     {
-        $this->cache->clear();
+        return $this->cache->clear();
     }
 
     /**

Tests/PrefixedSimpleCacheTest.php

@@ -71,7 +71,7 @@ public function testDelete()
         $key    = 'key';
         $result = true;
 
-        $stub = $this->getCacheStub('delete', [[$prefix.$key]], $result);
+        $stub = $this->getCacheStub('delete', [$prefix.$key], $result);
         $pool = new PrefixedSimpleCache($stub, $prefix);
 
         $this->assertEquals($result, $pool->delete($key));
@@ -134,7 +134,7 @@ public function testHas()
         $key    = 'key';
         $result = true;
 
-        $stub = $this->getCacheStub('has', [[$prefix.$key]], $result);
+        $stub = $this->getCacheStub('has', [$prefix.$key], $result);
         $pool = new PrefixedSimpleCache($stub, $prefix);
 
         $this->assertEquals($result, $pool->has($key));