Remove reference and dependency on System.ValueTuple (#351)

Author: Ivanidzo4ka

build/Dependencies.props

@@ -6,7 +6,6 @@
     <SystemThreadingTasksDataflowPackageVersion>4.8.0</SystemThreadingTasksDataflowPackageVersion>
     <SystemCodeDomPackageVersion>4.4.0</SystemCodeDomPackageVersion>
     <SystemReflectionEmitLightweightPackageVersion>4.3.0</SystemReflectionEmitLightweightPackageVersion>
-    <SystemValueTupleVersion>4.4.0</SystemValueTupleVersion>
     <PublishSymbolsPackageVersion>1.0.0-beta-62824-02</PublishSymbolsPackageVersion>
   </PropertyGroup>
 </Project>

pkg/Microsoft.ML/Microsoft.ML.nupkgproj

@@ -11,7 +11,6 @@
     <PackageReference Include="System.Reflection.Emit.Lightweight" Version="$(SystemReflectionEmitLightweightPackageVersion)" />
     <PackageReference Include="System.Threading.Tasks.Dataflow" Version="$(SystemThreadingTasksDataflowPackageVersion)" />
     <PackageReference Include="System.CodeDom" Version="$(SystemCodeDomPackageVersion)" />
-    <PackageReference Include="System.ValueTuple" Version="$(SystemValueTupleVersion)" />
   </ItemGroup>
 
   <ItemGroup>

src/Microsoft.ML/Microsoft.ML.csproj

@@ -9,7 +9,6 @@
   <ItemGroup>
     <PackageReference Include="System.CodeDom" Version="$(SystemCodeDomPackageVersion)" />
     <PackageReference Include="Newtonsoft.Json" Version="$(NewtonsoftJsonPackageVersion)" />
-    <PackageReference Include="System.ValueTuple" Version="$(SystemValueTupleVersion)" />
   </ItemGroup>
 
   <ItemGroup>