AssemblyInfo: Add InternalsVisibleTo for test project

Author: angularsen

UnitsNet/Properties/AssemblyInfo.cs

@@ -22,6 +22,7 @@
 using System;
 using System.Reflection;
 using System.Resources;
+using System.Runtime.CompilerServices;
 
 // General Information about an assembly is controlled through the following 
 // set of attributes. Change these attribute values to modify the information
@@ -37,6 +38,9 @@
 [assembly: AssemblyCulture("")]
 [assembly: NeutralResourcesLanguage("")]
 [assembly: CLSCompliant(true)]
+
+// Give access to internal members for testing
+[assembly: InternalsVisibleTo("UnitsNet.Tests")]
 // Version information for an assembly consists of the following four values:
 //
 //      Major Version