Fix approval tests.

Rx.NET/Source/tests/Tests.System.Reactive.ApiApprovals/Api/ApiApprovalTests.Aliases.verified.cs

@@ -1,7 +1,7 @@
 [assembly: System.CLSCompliant(true)]
 [assembly: System.Resources.NeutralResourcesLanguage("en-US")]
 [assembly: System.Runtime.InteropServices.ComVisible(false)]
-[assembly: System.Runtime.Versioning.TargetFramework(".NETFramework,Version=v4.6", FrameworkDisplayName=".NET Framework 4.6")]
+[assembly: System.Runtime.Versioning.TargetFramework(".NETFramework,Version=v4.7.2", FrameworkDisplayName=".NET Framework 4.7.2")]
 namespace System.Reactive.Linq
 {
     [System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]

Rx.NET/Source/tests/Tests.System.Reactive.ApiApprovals/Api/ApiApprovalTests.Core.verified.cs

@@ -3,7 +3,7 @@
 [assembly: System.Runtime.CompilerServices.InternalsVisibleTo(@"Tests.System.Reactive, PublicKey=00240000048000009400000006020000002400005253413100040000010001008f5cff058631087031f8350f30a36fa078027e5df2316b564352dc9eb7af7ce856016d3c5e9d058036fe73bb5c83987bd3fc0793fbe25d633cc4f37c2bd5f1d717cd2a81661bec08f0971dc6078e17bde372b89005e7738a0ebd501b896ca3e8315270ff64df7809dd912c372df61785a5085b3553b7872e39b1b1cc0ff5a6bc")]
 [assembly: System.Runtime.CompilerServices.InternalsVisibleTo(@"Tests.System.Reactive.Uwp.DeviceRunner, PublicKey=00240000048000009400000006020000002400005253413100040000010001008f5cff058631087031f8350f30a36fa078027e5df2316b564352dc9eb7af7ce856016d3c5e9d058036fe73bb5c83987bd3fc0793fbe25d633cc4f37c2bd5f1d717cd2a81661bec08f0971dc6078e17bde372b89005e7738a0ebd501b896ca3e8315270ff64df7809dd912c372df61785a5085b3553b7872e39b1b1cc0ff5a6bc")]
 [assembly: System.Runtime.InteropServices.ComVisible(false)]
-[assembly: System.Runtime.Versioning.TargetFramework(".NETFramework,Version=v4.6", FrameworkDisplayName=".NET Framework 4.6")]
+[assembly: System.Runtime.Versioning.TargetFramework(".NETFramework,Version=v4.7.2", FrameworkDisplayName=".NET Framework 4.7.2")]
 namespace System
 {
     public static class ObservableExtensions

Rx.NET/Source/tests/Tests.System.Reactive.ApiApprovals/Api/ApiApprovalTests.Testing.verified.cs

@@ -1,6 +1,6 @@
 [assembly: System.CLSCompliant(true)]
 [assembly: System.Runtime.InteropServices.ComVisible(false)]
-[assembly: System.Runtime.Versioning.TargetFramework(".NETFramework,Version=v4.6", FrameworkDisplayName=".NET Framework 4.6")]
+[assembly: System.Runtime.Versioning.TargetFramework(".NETFramework,Version=v4.7.2", FrameworkDisplayName=".NET Framework 4.7.2")]
 namespace Microsoft.Reactive.Testing
 {
     public interface ITestableObservable<T> : System.IObservable<T>