Add IAsyncDelayer

src/Tgstation.Server.Host/Core/IAsyncDelayer.cs

@@ -0,0 +1,20 @@
+using System;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace Tgstation.Server.Host.Core
+{
+	/// <summary>
+	/// For waiting asynchronously
+	/// </summary>
+	interface IAsyncDelayer
+	{
+		/// <summary>
+		/// Create a <see cref="Task"/> that completes after a given <paramref name="timeSpan"/>
+		/// </summary>
+		/// <param name="timeSpan">The <see cref="TimeSpan"/> that must elapse</param>
+		/// <param name="cancellationToken">The <see cref="CancellationToken"/> for the operation</param>
+		/// <returns>A <see cref="Task"/> representing the running operation</returns>
+		Task Delay(TimeSpan timeSpan, CancellationToken cancellationToken);
+	}
+}