updated libs

Author: Raul Hidalgo Caballero

tests/tests.props

@@ -8,9 +8,9 @@
 	</PropertyGroup>
 
 	<ItemGroup>
-		<PackageReference Include="Microsoft.NET.Test.Sdk" Version="15.7.2" />
-		<PackageReference Include="xunit" Version="2.3.1" />
-		<PackageReference Include="xunit.runner.visualstudio" Version="2.3.1" />
+		<PackageReference Include="Microsoft.NET.Test.Sdk" Version="15.8.0" />
+		<PackageReference Include="xunit" Version="2.4.0" />
+		<PackageReference Include="xunit.runner.visualstudio" Version="2.4.0" />
 	</ItemGroup>
 
 </Project>