Unify some dependency injection in a common library

TwilioSMSReceiver.Common/RegisterDI.cs

@@ -0,0 +1,24 @@
+using Microsoft.Extensions.DependencyInjection;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using TwilioSMSReceiver.Common.Handlers;
+using TwilioSMSReceiver.Common.Interfaces;
+
+namespace TwilioSMSReceiver.Common.Registrations
+{
+    public static class RegisterDI
+    {
+        /// <summary>
+        /// This registers all dependencies needed to support this app
+        /// </summary>
+        /// <param name="provider"></param>
+        public static void RegisterSMSExtensions(this IServiceCollection provider)
+        {
+            provider.AddScoped<IMessageHandler, SMTPHandler>();
+            provider.AddScoped<IMessageHandler, MSTeamsHandler>();
+        }
+    }
+}