Added functionality to save the stock cover art to a song if the song does not contain a cover art #50

Constants/DirectoryPaths.cs

@@ -0,0 +1,11 @@
+using System;
+using System.IO;
+
+namespace Icarus.Constants
+{
+    public class DirectoryPaths
+    {
+        public static string CoverArtPath =>
+            Directory.GetCurrentDirectory() + "/Images/Stock/CoverArt.png";
+    }
+}