Tweaks to tests

Author: egil

tests/Components/TestComponentBaseTest/BlazorElementReferencesIncludedInRenderedMarkup.razor

@@ -1,6 +1,5 @@
 @inherits TestComponentBase
 
-
 <Fixture Test="Test">
     <Fragment>
         <div @ref="refElm" />

tests/_Imports.razor

@@ -1,5 +1,9 @@
 @using Microsoft.AspNetCore.Components.Web
 @using Microsoft.Extensions.DependencyInjection
+@using Egil.RazorComponents.Testing
+@using Egil.RazorComponents.Testing.Asserting
+@using Egil.RazorComponents.Testing.EventDispatchExtensions
+@using Egil.RazorComponents.Testing.Mocking.JSInterop
 @using Egil.RazorComponents.Testing.SampleComponents
 @using Egil.RazorComponents.Testing.SampleComponents.Data
 @using Shouldly