Update samples to use Swagger / Swagger UI only in development environment.

[luisquintanilla]

Update the code in the Web API sample projects to only use Swagger / Swagger UI when in the development environment.

Original

machinelearning-samples/samples/csharp/end-to-end-apps/Forecasting-Sales/src/eShopDashboard/Startup.cs

Lines 97 to 101 in a262b18

	app.UseSwagger()
	.UseSwaggerUI(c =>
	{
	c.SwaggerEndpoint($"{ (!string.IsNullOrEmpty(pathBase) ? pathBase : string.Empty) }/swagger/v1/swagger.json", "eShopDashboard.API V1");
	});

Update code

https://github.com/dotnet/aspnetcore/blob/d594fc22076db3616a250817c3ca550fcbe69562/src/ProjectTemplates/Web.ProjectTemplates/content/WebApi-CSharp/Program.cs#L69-L73

if (app.Environment.IsDevelopment())
{
    app.UseSwagger();
    app.UseSwaggerUI();
}