Bump xunit from 2.6.6 to 2.7.0

Bumps [xunit](https://github.com/xunit/xunit) from 2.6.6 to 2.7.0.
- [Commits](xunit/xunit@2.6.6...2.7.0)

---
updated-dependencies:
- dependency-name: xunit
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

Tests.props

@@ -15,7 +15,7 @@
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.3.3" Condition="'$(TargetFramework)' == 'netcoreapp2.1'" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.8.0" Condition="'$(TargetFramework)' != 'netcoreapp2.1'" />
     <PackageReference Include="Shouldly" Version="4.2.1" />
-    <PackageReference Include="xunit" Version="2.6.6" />
+    <PackageReference Include="xunit" Version="2.7.0" />
     <PackageReference Include="xunit.runner.visualstudio" Version="2.4.3" Condition="'$(TargetFramework)' == 'netcoreapp2.1'" />
     <PackageReference Include="xunit.runner.visualstudio" Version="2.4.5" Condition="'$(TargetFramework)' == 'netcoreapp3.1' OR '$(TargetFramework)' == 'net5.0'" />
     <PackageReference Include="xunit.runner.visualstudio" Version="2.5.6" Condition="'$(TargetFramework)' != 'netcoreapp2.1' AND '$(TargetFramework)' != 'netcoreapp3.1' AND '$(TargetFramework)' != 'net5.0'" />