title: Cannot find AddMvc() in IServiceCollection in Visual Studio 2017
body: <p>I have created a brand new asp.net core application.
  I have added the mvc Nuget package yet I am getting the below error.</p>
  <p>Microsoft.AspNetCore.Mvc.Core 1.1.3</p>
  <blockquote>
  <p>'IServiceCollection' does not contain a definition for 'AddMvc' and no extension method 'AddMvc' accepting a first argument of type 'IServiceCollection' could be found (are you missing a using directive or an assembly reference?)**</p>
  </blockquote>