Release 4.0.0

• Drop support under Node 8
• Update babel version to 7
• Fix typescript support

Fix typescript issue

v4.0.0-rc.3

Release v4.0.0-rc.3

Fix typescript issue with redux-saga v1.1.1

v4.0.0-rc.2

Update readme and library version

First release candidate

It has been a while to stay on beta versions. It might be a good time to move towards a formal release.