Upgrade Notes for AspNetCore 3.0 Release Version

[kdcllc]

Notes for the upgrade ahead...

1. Upgrade Program.cs to support IHost builder impacts the DI for Startup.cs. The is no way to inject ILogger. .

• Adding Serilog to the ASP.NET Core Generic Host
• HostBuilder replaces WebHostBuilder

2. Upgrade Routing

• Update routing startup code

• Endpoint Routing updates starting Preview 4

• Routing in ASP.NET Core

• HealthChecks

                .Configure(app =>
                {
                    app.UseEndpoints(endpoints =>
                    {
                        endpoints.MapHealthChecks("/healthy");
                    });
                })

3. Upgrade To Nullable-references