Update newtonsoftjson (#160)

* update Newtonsoft.Json reference to 13.0.1

Closes #159

* Reference Microsoft.CSharp for all targets

Fixes error CS0656: Missing compiler required member 'Microsoft.CSharp.RuntimeBinder.Binder.Convert'

Author: mfkl

Consul/Consul.csproj

@@ -11,16 +11,16 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Newtonsoft.Json" Version="10.0.3" />
+    <PackageReference Include="Newtonsoft.Json" Version="13.0.1" />
     <PackageReference Include="ConfigureAwaitChecker.Analyzer" Version="5.0.0.1" PrivateAssets="All" />
+    <PackageReference Include="Microsoft.CSharp" Version="4.7.0"/>
   </ItemGroup>
 
   <ItemGroup Condition=" '$(TargetFrameworkIdentifier)' == '.NETFramework' ">
     <PackageReference Include="ILRepack" Version="2.0.18" PrivateAssets="All" />
     <PackageReference Update="Newtonsoft.Json" PrivateAssets="All" />
     <Reference Include="System.Net.Http" />
     <Reference Include="System.Net.Http.WebRequest" />
-    <Reference Include="Microsoft.CSharp" />
   </ItemGroup>
 
   <Target Name="ILRepack" AfterTargets="AfterBuild" Condition=" '$(TargetFrameworkIdentifier)' == '.NETFramework' ">