Update UnitTests.csproj

Updated UnitTests to also target net472

UnitTests/UnitTests.csproj

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFramework>net461</TargetFramework>
+    <TargetFramework>net472</TargetFramework>
   </PropertyGroup>
   <ItemGroup>
     <PackageReference Include="NUnit" Version="3.12.0" />