Targetting netstandard 2.0 also (#427)

Jint/Jint.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <NeutralLanguage>en-US</NeutralLanguage>
-    <TargetFrameworks>net40;net45;net451;netstandard1.3</TargetFrameworks>
+    <TargetFrameworks>net40;net45;net451;netstandard1.3;netstandard2.0</TargetFrameworks>
     <AssemblyOriginatorKeyFile>Jint.snk</AssemblyOriginatorKeyFile>
     <SignAssembly>true</SignAssembly>
   </PropertyGroup>
@@ -26,5 +26,6 @@
     <PackageReference Include="System.Runtime.InteropServices" Version="4.3.0" />
     <PackageReference Include="System.Xml.XmlDocument" Version="4.3.0" />
   </ItemGroup>
-
+  <ItemGroup Condition=" '$(TargetFramework)' == 'netstandard2.0' ">
+  </ItemGroup>
 </Project>