Fix netcoreapp1.1 target framework build

tests/Avalonia.Markup.UnitTests/Data/BindingExpressionTests.cs

@@ -51,8 +51,11 @@ namespace Avalonia.Markup.UnitTests.Data
         [Fact]
         public async void Should_Convert_Get_String_To_Double()
         {
+#if NET461
             Thread.CurrentThread.CurrentUICulture = CultureInfo.InvariantCulture;
-
+#else
+            CultureInfo.CurrentUICulture = CultureInfo.InvariantCulture;
+#endif
             var data = new Class1 { StringValue = "5.6" };
             var target = new BindingExpression(new ExpressionObserver(data, "StringValue"), typeof(double));
             var result = await target.Take(1);
@@ -83,7 +86,11 @@ namespace Avalonia.Markup.UnitTests.Data
         [Fact]
         public void Should_Convert_Set_String_To_Double()
         {
+#if NET461
             Thread.CurrentThread.CurrentUICulture = CultureInfo.InvariantCulture;
+#else
+            CultureInfo.CurrentUICulture = CultureInfo.InvariantCulture;
+#endif
 
             var data = new Class1 { StringValue = (5.6).ToString() };
             var target = new BindingExpression(new ExpressionObserver(data, "StringValue"), typeof(double));
@@ -96,7 +103,11 @@ namespace Avalonia.Markup.UnitTests.Data
         [Fact]
         public async void Should_Convert_Get_Double_To_String()
         {
+#if NET461
             Thread.CurrentThread.CurrentUICulture = CultureInfo.InvariantCulture;
+#else
+            CultureInfo.CurrentUICulture = CultureInfo.InvariantCulture;
+#endif
 
             var data = new Class1 { DoubleValue = 5.6 };
             var target = new BindingExpression(new ExpressionObserver(data, "DoubleValue"), typeof(string));
@@ -108,7 +119,11 @@ namespace Avalonia.Markup.UnitTests.Data
         [Fact]
         public void Should_Convert_Set_Double_To_String()
         {
+#if NET461
             Thread.CurrentThread.CurrentUICulture = CultureInfo.InvariantCulture;
+#else
+            CultureInfo.CurrentUICulture = CultureInfo.InvariantCulture;
+#endif
 
             var data = new Class1 { DoubleValue = 5.6 };
             var target = new BindingExpression(new ExpressionObserver(data, "DoubleValue"), typeof(string));
@@ -121,7 +136,11 @@ namespace Avalonia.Markup.UnitTests.Data
         [Fact]
         public async void Should_Return_BindingNotification_With_FallbackValue_For_NonConvertibe_Target_Value()
         {
+#if NET461
             Thread.CurrentThread.CurrentUICulture = CultureInfo.InvariantCulture;
+#else
+            CultureInfo.CurrentUICulture = CultureInfo.InvariantCulture;
+#endif
 
             var data = new Class1 { StringValue = "foo" };
             var target = new BindingExpression(
@@ -142,7 +161,11 @@ namespace Avalonia.Markup.UnitTests.Data
         [Fact]
         public async void Should_Return_BindingNotification_With_FallbackValue_For_NonConvertibe_Target_Value_With_Data_Validation()
         {
+#if NET461
             Thread.CurrentThread.CurrentUICulture = CultureInfo.InvariantCulture;
+#else
+            CultureInfo.CurrentUICulture = CultureInfo.InvariantCulture;
+#endif
 
             var data = new Class1 { StringValue = "foo" };
             var target = new BindingExpression(
@@ -163,7 +186,11 @@ namespace Avalonia.Markup.UnitTests.Data
         [Fact]
         public async void Should_Return_BindingNotification_For_Invalid_FallbackValue()
         {
+#if NET461
             Thread.CurrentThread.CurrentUICulture = CultureInfo.InvariantCulture;
+#else
+            CultureInfo.CurrentUICulture = CultureInfo.InvariantCulture;
+#endif
 
             var data = new Class1 { StringValue = "foo" };
             var target = new BindingExpression(
@@ -185,7 +212,11 @@ namespace Avalonia.Markup.UnitTests.Data
         [Fact]
         public async void Should_Return_BindingNotification_For_Invalid_FallbackValue_With_Data_Validation()
         {
+#if NET461
             Thread.CurrentThread.CurrentUICulture = CultureInfo.InvariantCulture;
+#else
+            CultureInfo.CurrentUICulture = CultureInfo.InvariantCulture;
+#endif
 
             var data = new Class1 { StringValue = "foo" };
             var target = new BindingExpression(