feat(*): Add SystemTime.Now method

Creek.HelpfulExtensions/Creek.HelpfulExtensions.csproj

@@ -19,8 +19,8 @@
     <PackageLicenseFile>LICENSE</PackageLicenseFile>
     <RepositoryType>git</RepositoryType>
     <PackageTags>creek</PackageTags>
-    <Version>1.1.0</Version>
-    <AssemblyVersion>1.1.0.0</AssemblyVersion>
+    <Version>1.2.0</Version>
+    <AssemblyVersion>1.2.0.0</AssemblyVersion>
   </PropertyGroup>
 
   <ItemGroup>

Creek.HelpfulExtensions/SystemTime.cs

@@ -0,0 +1,18 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace Creek.HelpfulExtensions
+{
+    public static class SystemTime
+    {
+        /// <summary>
+        /// This method exposes DateTime.Now as an instance of a function, that can be replaced in tests.
+        /// </summary>
+#pragma warning disable S1104 // Fields should not have public accessibility
+#pragma warning disable S2223 // Non-constant static fields should not be visible
+        public static Func<DateTime> Now = () => DateTime.Now;
+#pragma warning restore S2223 // Non-constant static fields should not be visible
+#pragma warning restore S1104 // Fields should not have public accessibility
+    }
+}