title: Custom Logger Provider being excluded by Serilog
body: <p>Serilog works great, but I noticed it seems to exclude any custom logger providers I setup. </p>
  
  <p>When I have <code>UseSerilog()</code> in my Startup, my CustomProvider never gets created (<code>CreateLogger</code> never gets called).</p>
  
  <p>Is it possible to still use custom providers with Serilog?</p>
  
  <pre><code>//class Program, Main Method
  WebHost.CreateDefaultBuilder(args)
      .UseConfiguration(config)
      .UseSerilog() //after adding this, my Custom Logger never gets called 
      .UseStartup&lt;Startup&gt;()
      .Build();
  
  
  //class Startup
  public void Configure(IApplicationBuilder app, ILoggerFactory logger, IServiceProvider serviceProvider)
  {
      logger.AddProvider(new CustomProvider(serviceProvider));
  }
  
  public class CustomProvider : ILoggerProvider
  {
      private readonly IServiceProvider _serviceProvider;
  
      public void Dispose()
      {
      }
  
      public CustomProvider(IServiceProvider serviceProvider)
      {
          _serviceProvider = serviceProvider;
      }
  
      //--------------never gets called---------------
      public ILogger CreateLogger(string categoryName)
      {
          var logger = _serviceProvider.GetService&lt;CustomLogger&gt;();
          logger.LogLevel = LogLevel.Error;
  
          return logger;
      }
  }
  </code></pre>