Add migration test from velo 0.0.84

test/LegacyTestApp/SquirrelLogger.cs

@@ -2,7 +2,27 @@
 
 namespace LegacyTestApp
 {
-    internal class SquirrelLogger : Squirrel.SimpleSplat.ILogger
+#if VELOPACK
+    using Microsoft.Extensions.Logging;
+    class SquirrelLogger : ILogger
+    {
+        public IDisposable BeginScope<TState>(TState state) where TState : notnull
+        {
+            return null;
+        }
+
+        public bool IsEnabled(LogLevel logLevel)
+        {
+            return true;
+        }
+
+        public void Log<TState>(LogLevel logLevel, EventId eventId, TState state, Exception exception, Func<TState, Exception, string> formatter)
+        {
+            Console.WriteLine(formatter(state, exception));
+        }
+    }
+#else
+    class SquirrelLogger : Squirrel.SimpleSplat.ILogger
     {
         protected SquirrelLogger()
         {
@@ -20,4 +40,5 @@ namespace LegacyTestApp
             Console.WriteLine(message);
         }
     }
+#endif
 }