Update tests

Author: mattjohnsonpint

test/TimeZoneConverter.Tests/IanaToWindowsTests.cs

@@ -47,7 +47,7 @@ public void Can_Convert_IANA_System_Zones_To_Windows()
         public void Can_Convert_Iana_Zones_To_Windows_Zones()
         {
             var errors = 0;
-            ICollection<string> ianaZones = TZConvert.KnownIanaTimeZoneNames;
+            ICollection<string> ianaZones = TZConvert.KnownIanaTimeZoneNames.ToList();
 
             string[] unmappable = { "Antarctica/Troll" };
 

test/TimeZoneConverter.Tests/RailsToIanaTests.cs

@@ -1,4 +1,5 @@
 using System.Collections.Generic;
+using System.Linq;
 using Xunit;
 using Xunit.Abstractions;
 
@@ -17,7 +18,7 @@ public RailsToIanaTests(ITestOutputHelper output)
         public void Can_Convert_Rails_Zones_To_Iana_Zones()
         {
             var errors = 0;
-            ICollection<string> railsZones = TZConvert.KnownRailsTimeZoneNames;
+            ICollection<string> railsZones = TZConvert.KnownRailsTimeZoneNames.ToList();
 
             foreach (string railsZone in railsZones)
             {

test/TimeZoneConverter.Tests/WindowsToIanaTests.cs

@@ -45,7 +45,7 @@ public void Can_Convert_Windows_System_Zones_To_Iana()
         public void Can_Convert_Windows_Zones_To_Iana_Golden_Zones()
         {
             var errors = 0;
-            ICollection<string> windowsZones = TZConvert.KnownWindowsTimeZoneIds;
+            ICollection<string> windowsZones = TZConvert.KnownWindowsTimeZoneIds.ToList();
 
             foreach (string windowsZone in windowsZones)
             {