Replace nancy with kestrel

Geekbot.net/WebApi/Logging/AspLogProvider.cs

@@ -0,0 +1,29 @@
+using System;
+using System.Collections.Concurrent;
+using Geekbot.net.Lib.Logger;
+using Microsoft.Extensions.Logging;
+
+namespace Geekbot.net.WebApi.Logging
+{
+    public class AspLogProvider : ILoggerProvider
+    {
+        private readonly IGeekbotLogger _geekbotLogger;
+        
+        private readonly ConcurrentDictionary<string, AspLogger> _loggers = new ConcurrentDictionary<string, AspLogger>();
+
+        public AspLogProvider(IGeekbotLogger geekbotLogger)
+        {
+            _geekbotLogger = geekbotLogger;
+        }
+        
+        public void Dispose()
+        {
+            _loggers.Clear();
+        }
+
+        public ILogger CreateLogger(string categoryName)
+        {
+            return _loggers.GetOrAdd(categoryName, name => new AspLogger(categoryName, _geekbotLogger));
+        }
+    }
+}