Automatic merge from submit-queue

Bump Cluster Autoscaler to 0.4.0

This is the  same binary as 0.4.0-beta1, that has been tested for the last couple weeks.

@saad-ali This should be cherry-picked to 1.5 release.

```release-note
Cluster Autoscaler in version 0.4.0
```

cc: @fgrzadkowski @piosz @jszczepkowski