Upgrade to elasticsearch-net v6

[EamonHetherton]

A few questions before you begin:

Is this an issue related to the Serilog core project or one of the sinks or
community projects.
This issue list is intended for Serilog Elasticsearch Sink issues. If this issue relates to another sink or to the code project,
please log on the related repository. Please use Gitter chat and Stack Overflow for discussions and questons.

Does this issue relate to a new feature or an existing bug?

• Bug
• New Feature

What version of Serilog.Sinks.Elasticsearch is affected? Please list the related NuGet package.

What is the target framework and operating system? See target frameworks & net standard matrix.

• netCore 2.0
• netCore 1.0
• 4.7
• 4.6.x
• 4.5.x

Please describe the current behavior?

Please describe the expected behavior?

If the current behavior is a bug, please provide the steps to reproduce the issue and if possible a minimal demo of the problem

[EamonHetherton]

Currently due to a breaking change in a constructor for Elasticsearch.Net.ConnectionConfiguration in elasticsearch-net v6 I get a System.MissingMethodException when trying to use this sink in a project that references elasticsearch-net v6

[DaveNW16HD]

Hi, is there an update to when v6 release will occur ?

[mivano]

I pushed the master branch so a release version is available.