To build Snip you'll need to create your own ApplicationKeys.cs file.
The contents of the file should be as follows.
namespace Winter
{
public static class ApplicationKeys
{
public static string SpotifyClientId = "";
public static string SpotifyClientSecret = "";
public static string Spotify = Convert.ToBase64String(Encoding.UTF8.GetBytes(string.Format("{0}:{1}", SpotifyClientId, SpotifyClientSecret)));
}
}