Fix bug

Author: dereuromark

src/ImageVariant.php

@@ -237,7 +237,7 @@ public function cover(
         bool $preventUpscale = false,
         string $position = 'center'
     ): self {
-        $this->operations['fit'] = [
+        $this->operations['cover'] = [
             'width' => $width,
             'height' => $height,
             'callback' => $callback,

src/Operations.php

@@ -278,6 +278,6 @@ public function callback(array $arguments): void
             );
         }
 
-        $arguments['callable']($this->image, $arguments);
+        $arguments['callback']($this->image, $arguments);
     }
 }