Automatic merge from submit-queue
Fix/centos docker download
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**What this PR does / why we need it**: The CentOS cluster provider attempts to download docker from a location that 404's.
**Which issue this PR fixes**: addresses https://github.com/kubernetes/kubernetes/issues/27572#issuecomment-226690177
**Special notes for your reviewer**: I don't know how Kubernetes decides docker compatibility, but it was previously pulling `latest` so I chose the most recent release. Is there any mechanism for keeping things like this up to date?
What is the status of kubernetes rpm's? As far as I could tell there aren't any 1.3 rpm's published. Are those officially supported or a community project?
**Release note**:
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```release-note
CentOS Cluster Provider: fix docker download location & use docker 1.12.0
```
Matthias Bertschy