* Support for Docker version 1.9.x has been removed
* rkt version 1.23.0+
  * known issues with the rkt runtime are [listed in the Getting Started Guide](http://kubernetes.io/docs/getting-started-guides/rkt/notes/)
* etcd version 3.0.17
## Changelog since v1.6.0-rc.1


### Previous Releases Included in v1.6.0

* For issues with Docker 1.13.X please see the [1.13.X tracking issue](https://github.com/kubernetes/kubernetes/issues/42926)

* rkt version 1.23.0+

    * known issues with the rkt runtime are [listed in the Getting Started Guide](https://kubernetes.io/docs/getting-started-guides/rkt/notes/)

* etcd version 3.0.17

- k8s.io/utils: 581e001 → e782cd3
- sigs.k8s.io/structured-merge-diff: 6149e45 → b1b620d

#### Removed
- github.com/cloudflare/cfssl: 56268a6
- github.com/coreos/bbolt: v1.3.3
- github.com/coreos/rkt: v1.30.0
- github.com/globalsign/mgo: eeefdec
- github.com/google/certificate-transparency-go: v1.0.21
- github.com/heketi/rest: aa6a652
- github.com/heketi/utils: 435bc5b
- github.com/pborman/uuid: v1.2.0

    *   Passed all CRI validation conformance tests and node end-to-end conformance tests.
*   [alpha] [rktlet](https://github.com/kubernetes-incubator/rktlet): CRI implementation for the rkt runtime is now v0.1.0. [[@iaguis](https://github.com/iaguis)]
    *   This is the first release of rktlet and it implements support for the CRI including fetching images, running pods, CNI networking, logging and exec.