Release 6.0.0

This is the first GA release of the 6.x release cycle. For breaking change make sure to also check the 6.0.0-beta1 release.

Backward Compatibility Breaks

• Return the _source of inner hit nested as is without wrapping it into its full path context #1398
• Removed CrossIndex Class as from now use Reindex. #1411

Added

• Added clear() to Scroll for closing search context on ES manually
• Added Elastica\Aggregation\StatsBucket

Improvements

• Clear search context on ES after usage in Scroll