Also reset scenarios when the mappings are reset.

src/WireMock.Net/Server/FluentMockServer.Admin.cs

@@ -120,7 +120,6 @@ namespace WireMock.Server
             Given(Request.Create().WithPath(AdminRequests + "/find").UsingPost()).RespondWith(new DynamicResponseProvider(RequestsFind));
 
 
-            // __admin/scenarios
             // __admin/scenarios
             Given(Request.Create().WithPath(AdminScenarios).UsingGet()).RespondWith(new DynamicResponseProvider(ScenariosGet));
             Given(Request.Create().WithPath(AdminScenarios).UsingDelete()).RespondWith(new DynamicResponseProvider(ScenariosReset));
@@ -346,6 +345,8 @@ namespace WireMock.Server
         {
             ResetMappings();
 
+            ResetScenarios();
+
             return new ResponseMessage { Body = "Mappings deleted" };
         }
         #endregion Mappings

src/WireMock.Net/Server/FluentMockServer.cs

@@ -1,5 +1,4 @@
 using System;
-using System.Collections;
 using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.Collections.ObjectModel;