Stability Release

• Updated to use the latest libanius-akka library, i.e. version 0.4.

• Ensured sessions and cookies don't expire.

• Added Akka TestKit tests.

Libanius ScalaJs React Akka

• Manually forked libanius-scalajs-react. (It could have been a branch but a fork is a bit
  more accessible and a bit less error-prone.) It progresses from the version number of the
  original, but the functionality and version numbers may diverge.

• This fork uses Akka Cluster. Also, instead of the libanius library, it is built on the
  libanius-akka library, which uses Akka Persistence.

• The main new classes are QuizUsersService, QuizUsersGateway, and QuizForUserSharding. The
  last maintains the cluster of QuizForUserActor's.

• The feature whereby a user could save quiz data to local disk has been removed, at least
  temporarily. Data is kept on the server in an event-sourcing journal.