title: Issue with IAppBuilder assembly reference
body: <p>I am trying to find out the why I cant use the IAppBuilder. I have add many assemblies to my project but still taking the error ” The type or namespace name 'IAppBuilder' could not be found (are you missing a using directive or an assembly reference?)”
  My goal is by using AsterNet library to connect with a Asterisk Server and create conference rooms. The code that i am using is :</p>
  
  <pre><code> using System;
   using Microsoft.Owin;
   using Owin;
   using System.Net.Http;
   using System.Web.Http;
   using System.Web.Http.Routing;
   using AsterNET;
   using AsterNET.ARI;
   using AsterNET.ARI.SimpleConfExample.REST;
   using Microsoft.AspNet.SignalR.Owin;
  
   namespace AsterNET.ARI.SimpleConfExample.REST
  
  {
  public class Startup
  {
      // This code configures Web API. The Startup class is specified as a type
      // parameter in the WebApp.Start method.
  
      public void Configuration(IAppBuilder appBuilder)
      {
          // Configure Web API for self-host. 
          var config = new HttpConfiguration();
  
          //config.Routes.MapHttpRoute(
          //    name: "DefaultApi",
          //    routeTemplate: "api/{controller}/{id}",
          //    defaults: new { id = RouteParameter.Optional }
          //);
  
          //config.Routes.MapHttpRoute(
          //    name: "DefaultApiWithAction",
          //    routeTemplate: "api/{controller}/{id}/{action}",
          //    defaults: new { action = "Get" },
          //    constraints: new { HttpCons}
          //);
  
          config.Routes.MapHttpRoute(
              name: "DefaultApi",
              routeTemplate: "api/{controller}/{id}/{action}"
          );
  
          config.Routes.MapHttpRoute(
              name: "DefaultApiWithId",
              routeTemplate: "api/{controller}/{id}",
              defaults: new { action = "Get" },
              constraints: new { httpMethod = new HttpMethodConstraint(HttpMethod.Get) }
          );
  
          config.Routes.MapHttpRoute(
              name: "DefaultApiGet",
              routeTemplate: "api/{controller}/",
              defaults: new { action = "Get" },
              constraints: new { httpMethod = new HttpMethodConstraint(HttpMethod.Get) }
          );
  
          config.Routes.MapHttpRoute(
              name: "DefaultApiPost",
              routeTemplate: "api/{controller}/",
              defaults: new { action = "Post" },
              constraints: new { httpMethod = new HttpMethodConstraint(HttpMethod.Post) }
          );
  
          config.Routes.MapHttpRoute(
              name: "DefaultApiDelete",
              routeTemplate: "api/{controller}/{id}",
              defaults: new { action = "Delete" },
              constraints: new { httpMethod = new HttpMethodConstraint(HttpMethod.Delete) }
          );
          appBuilder.UseWebApi(config);
      }
  } 
  }
  </code></pre>