SPECS2-4.3.6

Maintenance version

Enhancements

• removed the `oracle-java9-installer (#722) (kenji yoshida)
• added the possibility to use Futures in immutable specs
• added the possibility to return a Future[Result] from an example
• better reporting when stats files cannot be written (#716)

Upgrades

• use cats-1.5.0, cats-effect 1.1.0 (#726) (kenji yoshida)
• use mockito-2.23.4 (#725) (kenji yoshida)
• use scalaz-7.2.27, kind-projector-0.9.9 (#723) (kenji yoshida)