position_offset_gap renamed to position_increment_gap

[stromblom]

Elastic version: 2.2.0
Nest version: 2.1.0

When setting position_offset_gap on the StringAttribute Elastic will generate an error on the PUT:

"Mapping definition for [names] has unsupported parameters: [position_offset_gap : 100]"

Seems it has been renamed to: position_increment_gap

https://www.elastic.co/guide/en/elasticsearch/reference/2.2/release-notes-2.0.0-beta2.html#breaking-2.0.0-beta2

[gmarz]

Thanks for the heads up @stromblom, we'll fix this asap.

[gmarz]

Closed via 48a2200 and 2090369