updated elasticsearch upstream to fix flaky tests
checkout es/upstream feature branch
added ArrayMapper for handling array fields
add custom array type to ES type parsers
Inject ArrayMapper, so es uses it to handle dynamic arrays.
updated array mapping for create / alter table
prevent nested arrays from being defined in the mapping or inserted (even via copy from)
correctly handle null values and nested objects

* support parsing null values
* reset path in ParseContext after traversing into ObjectMapper during parsing of document source
removed writing of collection_type to meta info because
array handling changed
recognize new array mapping when parsing IndexMetaData

break support for writing collection_type into _meta
added ArrayMapper for handling array fields
migrate old index mapping to new array type mapping