.ConfigureAwait(false) all async/await methods

[russcam]

Since none of our async methods need to callback on the context, we should configure all async calls not to capture it.

[niemyjski]

I took a look at the source code and it looks like you are missing them in quite a few spots: Here is one of them: https://github.com/elastic/elasticsearch-net/blob/master/src/Nest/Document/Multiple/BulkAll/BulkAllObservable.cs#L111 and pretty much every call to await Task.Delay(x). You may want to do a search for await the project and then in the find window search for configureawait and if you don't see one on every result line... You may be missing a spot.