Timestamp field should be removed from fluent mappings

[niemyjski]

https://www.elastic.co/guide/en/elasticsearch/reference/current/mapping-timestamp-field.html it's no longer supported. It actually throws an error when you try to run a mapping with it.

.TimestampField(ts => ts.Enabled().Path(u => u.UpdatedUtc).IgnoreMissing(false))

[niemyjski]

The same goes for IncludeInAll

[gmarz]

Another one we''ll have to mark obsolete and remove in 5.x. Although, it should only be deprecated in ES 2.x...

[niemyjski]

I think there are more that we are missing. Might want to go through all the docs and ensure we are deprecated everywhere.. This has made upgrading a pain point.

[gmarz]

Closing in favor of #1988