migrated the obsolete xproj to the new csproj and updated nuget packages

[tamirdresher]

Migrated the obsolete xproj to the new csproj (https://docs.microsoft…com/en-us/dotnet/core/migration/).

Updated nuget packages ( #21 ):

• loggly-csharp 4.6.0.5 --> 4.6.1.45
• Newtonsoft.Json 9.0.1 --> 10.0.3
• Serilog 2.0.0 --> 2.5.0
• Serilog.Sinks.PeriodicBatching 2.0.0 --> 2.1.1
• Serilog.Sinks.File 3.1.1 --> 3.2.0
• Serilog.Sinks.RollingFile 3.2.0 --> 3.3.0
• Serilog.Sinks.RollingFileAlternate 2.0.6 --> 2.0.9
• Serilog.Sinks.Async 1.0.1 --> 1.1.0
• Serilog.Enrichers.Environment 2.1.1 --> 2.1.2
• Serilog.Enrichers.Process 2.0.0 --> 2.0.1

[nblumhardt]

Great 👍

Issue with the build:

Collecting artifacts...
No artifacts found matching 'artifacts\Serilog.*.nupkg' path
Build success

The Serilog projects all generally use the same standardized Build.ps1 file - grabbing e.g. https://github.com/serilog/serilog-sinks-console/blob/dev/Build.ps1 and copying it in directly should fix this.

[tamirdresher]

@nblumhardt I reverted the Build.ps1 back to what it was. But i had to change the appveyor.yml in order to use the VS2017 image. Everything works the same as it was now.

[nblumhardt]

@tamirdresher awesome, merged!

I am going to bump the dev package version to 5.1 to reflect some change going on under the hood.

[tamirdresher]

Thanks @nblumhardt I'm happy that i could help. Looking forward to use the new package