title: RouteAttribute can't be found in System.Web.Http package
body: <p>I've added the <code>ASP.NET web API self host</code> using the NuGet package manager to my project (a windows service project)
  the Nuget added those libraries</p>
  
  <ul>
  <li>ASP.NET web API self host</li>
  <li>Json.NET</li>
  <li>Microsoft .NET framework 4 HTTP Client libraries</li>
  <li>Microsoft ASP.NET Web API Client/Core libraries</li>
  <li>Microsoft ASP.NET Web API Self Host</li>
  </ul>
  
  <p>When I try to add Route attribute I can't find it in the System.Web.Http. 
  when i looked for this class in MSDN i saw its under this <a href="https://msdn.microsoft.com/en-us/library/system.web.http.routeattribute%28v=vs.118%29.aspx" rel="nofollow">package</a></p>
  
  <p>do i need to install another package or add another referance?</p>