Support Microsoft.AspNetCore for net 4.6.1 and up (#185)

* net451

* tests : net462

* fixed tests

* fix tests

* readme

* Code review

* LocalFileSystemHandlerTests

* refactor

examples/WireMock.Net.Console.Net452.Classic/Program.cs

@@ -0,0 +1,15 @@
+using System.IO;
+using log4net.Config;
+
+namespace WireMock.Net.ConsoleApplication
+{
+    static class Program
+    {
+        static void Main(params string[] args)
+        {
+            XmlConfigurator.Configure(new FileInfo("log4net.config"));
+
+            MainApp.Run();
+        }
+    }
+}