Consolidate Microsoft.NET.Test.Sdk and all things xUnit across all projects. (#609)

Rx.NET/Source/tests/Tests.System.Reactive.Uwp.DeviceRunner/Tests.System.Reactive.Uwp.DeviceRunner.csproj

@@ -91,7 +91,7 @@
   </PropertyGroup>
   <ItemGroup>
     <PackageReference Include="Microsoft.NETCore.UniversalWindowsPlatform" Version="6.0.8" />
-    <PackageReference Include="xunit" Version="2.3.1" />
+    <PackageReference Include="xunit" Version="2.4.0-beta.2.build4010" />
     <PackageReference Include="xunit.runner.devices" Version="2.3.3" />
   </ItemGroup>
   <ItemGroup>

Rx.NET/Source/tests/Tests.System.Reactive/Tests.System.Reactive.csproj

@@ -15,9 +15,9 @@
     <Reference Include="WindowsBase" />
   </ItemGroup>
   <ItemGroup>
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="15.6.0" />    
-    <PackageReference Include="xunit" Version="2.4.0-beta.2.build3981" />
-    <PackageReference Include="xunit.runner.visualstudio" Version="2.4.0-beta.2.build3981" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="15.7.2" />    
+    <PackageReference Include="xunit" Version="2.4.0-beta.2.build4010" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="2.4.0-beta.2.build4010" />
     <DotNetCliToolReference Include="dotnet-xunit" Version="2.4.0-beta.2.build3981" />
     <ProjectReference Include="..\..\src\System.Reactive\System.Reactive.csproj" />
     <ProjectReference Include="..\..\src\System.Reactive.Observable.Aliases\System.Reactive.Observable.Aliases.csproj" />