Add correct versions of Microsoft.NETFramework.ReferenceAssemblies to fix build

Author: lukebakken

projects/client/RabbitMQ.Client.WinRT/RabbitMQ.Client.WinRT.csproj

@@ -73,7 +73,7 @@
     <Compile Include="src\util\Timer.cs" />
   </ItemGroup>
   <ItemGroup>
-    <!-- A reference to the entire .Net Framework and Windows SDK are automatically included -->
+    <PackageReference Include="Microsoft.NETFramework.ReferenceAssemblies" Version="1.0.0" PrivateAssets="All" />
   </ItemGroup>
   <!-- Mono compatibility workarounds -->
   <!-- Microsoft Windows 8 CSharp targets -->
@@ -85,4 +85,4 @@
   <Target Name="BeforeBuild" DependsOnTargets="" />
   <!-- Custom BeforeClean -->
   <Target Name="BeforeClean" DependsOnTargets="" />
-</Project>
+</Project>

projects/client/Unit.WinRT/Unit.WinRT.csproj

@@ -15,6 +15,7 @@
 
   <ItemGroup>
     <PackageReference Include="NUnit" Version="3.4.1" />
+    <PackageReference Include="Microsoft.NETFramework.ReferenceAssemblies" Version="1.0.0" PrivateAssets="All" />
   </ItemGroup>
 
   <ItemGroup Condition=" '$(TargetFramework)' == 'net45' ">

projects/client/Unit/Unit.csproj

@@ -22,11 +22,10 @@
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.2.0" />
     <PackageReference Include="NUnit" Version="3.12.0" />
     <PackageReference Include="NUnit3TestAdapter" Version="3.15.1" />
-    <!--<PackageReference Include="PublicApiGenerator" Version="8.1.0" />-->
     <PackageReference Include="Mono.Cecil" Version="0.10.3" />
-
     <PackageReference Include="System.Runtime" Version="4.3.0" />
     <PackageReference Include="System.Collections.NonGeneric" Version="4.3.0" />
+    <PackageReference Include="Microsoft.NETFramework.ReferenceAssemblies" Version="1.0.0" PrivateAssets="All" />
   </ItemGroup>
 
   <PropertyGroup Condition=" '$(TargetFramework)' == 'netcoreapp2.1' ">