Send Journald logs to AWS CloudWatch (kubernetes-retired#707)

A service has been introduced which runs a dockerised image of journald-cloudwatch-logs. This service forwards journald logs to AWS CloudWatch to a LogGroup with the name of .ClusterName and is run on all nodes (Etcds, Controllers and Workers).

journald-cloudwatch-logs is a goLang project https://github.com/saymedia/journald-cloudwatch-logs.

This feature is disabled by default and configurable in cluster.yaml:

```
cloudWatchLogging:
 enabled: false
 retentionInDays: 7

 journaldCloudWatchLogsImage: jollinshead/journald-cloudwatch-logs:0.1
```

Merge pull request kubernetes-retired#697 from mumoshu/fix-ca-not-sca…

…ling-down

Fix the issue that cluster-autoscaler never scale-down the cluster

Merge pull request kubernetes-retired#671 from camilb/fix-ca

Fix "install-kube-system" script when "clusterAutoscaler" is disabled.

Merge pull request kubernetes-retired#629 from mumoshu/re-cluster-aut…

…oscaler

Re: cluster-autoscaler support

Merge pull request kubernetes-retired#613 from simonwydooghe/patch-1

Fix typo in command listing

Merge pull request kubernetes-retired#613 from simonwydooghe/patch-1

Fix typo in command listing

Merge pull request kubernetes-retired#610 from mumoshu/fix-efs-per-no…

…de-pool

Fix elasticFileSystemId only on node pools

Merge pull request kubernetes-retired#590 from mumoshu/fix-etcd-snaps…

…hot-s3-loc

Fix etcd snapshots locations in S3

Merge pull request kubernetes-retired#554 from mumoshu/deprecate-exte…

…rnal-dns-name-create-record-set-hosted-zone-id

Deprecate externalDNSName/createRecordSet/hostedZoneId

Merge pull request kubernetes-retired#563 from HotelsDotCom/etcd-cfn-…

…signal-retry

Make cfn-signal more robust against image fetch failures