added first version of m3u parser (only parse what we need)

Parser/IPlaylistParser.cs

@@ -0,0 +1,11 @@
+using System.Collections.Generic;
+using System.IO;
+using System.Threading.Tasks;
+
+namespace Tv7Playlist.Parser
+{
+    public interface IPlaylistParser
+    {
+        Task<IReadOnlyCollection<ParsedTrack>> ParseFromStream(Stream stream);
+    }
+}