Update ProviderCacher.php

fixed error  Undefined property: KevBaldwyn\Image\Cache\ProviderCacher::$publicPath  in KevBaldwyn/Image/Cache/ProviderCacher.php:22

src/KevBaldwyn/Image/Cache/ProviderCacher.php

@@ -9,6 +9,7 @@ class ProviderCacher implements CacherInterface {
 	protected $imgPath;
 	protected $operations;
 	protected $cacheLifetime;
+	protected $publicPath;
 
 
 	public function __construct(ProviderInterface $provider)
@@ -28,6 +29,8 @@ public function init($imgPath, $operations, $cacheLifetime, $publicPath)
 		$this->imgPath       = $imgPath;
 		$this->operations    = $operations;
 		$this->cacheLifetime = $cacheLifetime;
+		$this->publicPath = $publicPath;
+
 	}
 
 
@@ -55,4 +58,4 @@ public function put($cacheData)
 		$this->provider->putToCache($this->checksum, $cacheData, $this->cacheLifetime);
 	}
 
-}
+}