Updating tests librairies. (#12)

Author: alexandrejulien

tests/AspNetCore.SecurityHeaders.Addons.Tests/Peppermint.AspNetCore.SecurityHeaders.Addons.Tests.csproj

@@ -10,9 +10,9 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.7.2" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.8.0" />
     <PackageReference Include="NFluent" Version="3.0.1.352" />
-    <PackageReference Include="xunit" Version="2.6.0" />
+    <PackageReference Include="xunit" Version="2.6.1" />
     <PackageReference Include="xunit.runner.visualstudio" Version="2.5.3">
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
       <PrivateAssets>all</PrivateAssets>