update sample for preview 3 (#54)

Author: analogrelay

WindowsUniversal/WindowsUniversal/WindowsUniversal.csproj

@@ -128,17 +128,11 @@
     </Page>
   </ItemGroup>
   <ItemGroup>
-    <PackageReference Include="System.Threading.Tasks.Extensions">
-      <Version>4.5.1</Version>
-    </PackageReference>
-    <PackageReference Include="System.Runtime.CompilerServices.Unsafe">
-      <Version>4.5.1</Version>
-    </PackageReference>
     <PackageReference Include="Microsoft.AspNetCore.SignalR.Client">
-      <Version>1.0.1</Version>
+      <Version>1.1.0-preview3-35497</Version>
     </PackageReference>
     <PackageReference Include="Microsoft.Extensions.Logging.Debug">
-      <Version>2.1.0</Version>
+      <Version>2.2.0-preview3-35497</Version>
     </PackageReference>
     <PackageReference Include="Microsoft.NETCore.UniversalWindowsPlatform">
       <Version>6.1.5</Version>