title: IHostBuilder does not contain a definition for ConfigureWebHostDefaults
body: <p>I'm trying to use the new <code>GenericHost</code> in <strong>.NET Core 3.0</strong> documented <a href="https://docs.microsoft.com/en-us/aspnet/core/fundamentals/host/generic-host?view=aspnetcore-3.0" rel="noreferrer">here</a> but I'm getting a really basic error that stats <code>IHostBuilder</code> does not contain a definition for the <code>ConfigureWebHostDefaults</code> function.</p>
  
  <p>Looking at the <strong>ASP.NET 3.0</strong> documentation here for the <code>IHostBuilder</code> interface <a href="https://docs.microsoft.com/en-us/dotnet/api/microsoft.extensions.hosting.ihostbuilder?view=aspnetcore-3.0" rel="noreferrer">here</a> I cant see any reference to <code>ConfigureWebHostDefaults</code> so I'm a bit confused.</p>
  
  <p>I'm using the 3.0.0 packages for <code>Microsoft.Extensions.Hosting</code> and <code>Microsoft.Extensions.Hosting.Abstractions</code> but cant help but feel I'm either missing something really obvious or that <code>ConfigureWebHostDefaults</code> has for some reason been removed?</p>
  
  <p>Update -- Screen shot of Program.cs</p>
  
  <p><a href="https://i.stack.imgur.com/o1bda.png" rel="noreferrer"><img src="https://i.stack.imgur.com/o1bda.png" alt="enter image description here"></a></p>
  
  <p>Update -- .csproj file </p>
  
  <pre><code>&lt;Project Sdk="Microsoft.NET.Sdk"&gt;
  
    &lt;PropertyGroup&gt;
      &lt;OutputType&gt;Exe&lt;/OutputType&gt;
      &lt;TargetFramework&gt;netcoreapp3.0&lt;/TargetFramework&gt;
    &lt;/PropertyGroup&gt;
  
    &lt;ItemGroup&gt;
      &lt;PackageReference Include="Microsoft.AspNetCore.Hosting" Version="2.2.7" /&gt;
      &lt;PackageReference Include="Microsoft.Extensions.Hosting" Version="3.0.0" /&gt;
      &lt;PackageReference Include="Microsoft.Extensions.Hosting.Abstractions" Version="3.0.0" /&gt;
    &lt;/ItemGroup&gt;
  
  &lt;/Project&gt;
  </code></pre>