Revert etcd upgrade

[omar-nahhas]

Etcd was upgraded from version 3.2.13 to version 3.3.10 on this PR e8b7380.

After testing an upgrade from a cluster created with kube-aws 0.12.X to kube-aws master, we have found that, if there is a problem during the upgrade, cloud formation is not able to rollback cleanly, and etcd cluster is left on an unavailable state due to being unable to downgrade etcd.

This is PR Is to revert the etcd upgrade version back to 3.2.13 until a two ways migration is implemented.

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[omar-nahhas]

/assign @davidmccormick

[davidmccormick]

@omar-nahhas thanks for your testing efforts and work identifying this issue! I agree, let's keep etcd on a stable version until we can implement a smoother path forward with upgrades.

[codecov-io]

Codecov Report

Merging #1555 into master will decrease coverage by 0.01%.
The diff coverage is 20%.

@@            Coverage Diff             @@
##           master    #1555      +/-   ##
==========================================
- Coverage   25.47%   25.46%   -0.02%     
==========================================
  Files          97       97              
  Lines        5016     5019       +3     
==========================================
  Hits         1278     1278              
- Misses       3591     3594       +3     
  Partials      147      147

Impacted Files	Coverage Δ
pkg/api/plugin.go	0% <ø> (ø)	⬆️
pkg/model/stack_new.go	32.29% <0%> (-0.62%)	⬇️
pkg/api/etcd.go	34.02% <100%> (ø)	⬆️

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[davidmccormick]

Many thanks for your investigation and fix! 🙏

[omar-nahhas]

Here are some results of manual testing I have done:
1 - create the cluster using kube 0.12

2 - try upgrade to kube 0.13, cause a rollback, and observe a successful rollback.

3 - cluster is healthy after rollback