Update Serilog to v2;

[jwhitex]

Version Matches MassTransit.SerilogIntegration Serilog version. Resolves #348, #342, and #346.

[jwhitex]

@phatboyg We suspect using Serilog v1 in our Topshelf project has something to do with not getting logs when exceptions are thrown in MassTransit consumers. Note that we are setting the global Log.Logger with a Serlog v1 logger and applying the UseSerilog() extension on both the bus and the service 'Configurator'.

[waynebrantley]

Any chance of getting this closed and a new build published?

[phatboyg]

Yeah, soon for sure.

[ar1k]

I think this PR needs in one more change. Because the memory buffer may contain events that have not yet been written to the target sink, it is important to call Log.CloseAndFlush(), and appropriate place is Shutdown() in SerilogLogWriterFactory.cs. Hope PR will be accepted soon after that :)

[phatboyg]

Sounds good to me. Will get to this after the vs2017 branch is merged.

[ar1k]

@phatboyg, Is there any chance that the request will be accepted soon?

[stefanopretto]

@phatboyg I second the request, I would really love to be able to use the latest Serilog version with Topshelf.

[stephenpatten]

@phatboyg is the goal to be backwards compatible, or is this a nuget issue?

[phatboyg]

I'll get it merged soon. I need to update Topshelf anyway.