update.csproj

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <Description>Nancy is a lightweight web framework for the .Net platform, inspired by Sinatra. Nancy aim at delivering a low ceremony approach to building light, fast web applications.</Description>
    <TargetFrameworks>netstandard1.6;net452</TargetFrameworks>
  </PropertyGroup>

  <ItemGroup>
    <EmbeddedResource Include="ErrorHandling\Resources\**\*.*;Diagnostics\Resources\**\*.*;Diagnostics\Views\**\*.*" Exclude="bin\**;obj\**;**\*.xproj;packages\**;@(EmbeddedResource)" />
  </ItemGroup>

  <ItemGroup Condition=" '$(TargetFramework)' == 'netstandard1.6' ">
    <PackageReference Include="Microsoft.Extensions.DependencyModel" Version="1.1.1" />
    <PackageReference Include="Microsoft.AspNetCore.App" />
    <PackageReference Include="Microsoft.Extensions.PlatformAbstractions" Version="1.1.0"></PackageReference>
    <PackageReference Include="System.Collections.Specialized"><Version>4.3.0</Version></PackageReference>
    <!-- marks all packages as 'local only' so they don't end up in the nuspec -->
    <PackageReference Update="@(PackageReference)" PrivateAssets="All" />
  </ItemGroup>

  <ItemGroup Condition=" '$(TargetFramework)' == 'net452' ">
    <Reference Include="System.Xml" />
  </ItemGroup>
</Project>