K8s improvments march 2019

[godber]

This PR addresses the following things

• update kubernetes-client #1032 - update kubernetes-client
• Allow teraslice job to override the teraslice version in k8s #1002 - allow jobs to specify teraslice image name
• Teraslice worker versions should report NA in k8s clustering #981 - report pod image in cluster state, improved /txt/workers

[codecov]

Codecov Report

Merging #1033 into master will decrease coverage by 0.01%.
The diff coverage is 78.94%.

@@            Coverage Diff             @@
##           master    #1033      +/-   ##
==========================================
- Coverage   69.26%   69.25%   -0.02%     
==========================================
  Files         286      286              
  Lines       10302    10307       +5     
  Branches      477      477              
==========================================
+ Hits         7136     7138       +2     
- Misses       3059     3062       +3     
  Partials      107      107

Impacted Files	Coverage Δ
...ervices/cluster/backends/kubernetes/k8sResource.js	98.43% <100%> (+0.02%)	⬆️
packages/job-components/src/job-schemas.ts	61.4% <100%> (+0.68%)	⬆️
...luster/services/cluster/backends/kubernetes/k8s.js	55.38% <100%> (ø)	⬆️
...r/services/cluster/backends/kubernetes/k8sState.js	100% <100%> (ø)	⬆️
packages/teraslice/lib/cluster/services/api.js	22.92% <20%> (+0.03%)	⬆️

[godber]

Since I got these done this week, I'm going to move these changes to the v0.50.0 milestone since that's not out yet. @peterdemartini if you can do a quick review ... if it passes without requests for changes, please merge it. If it doesn't, I'll be back monday to address changes and it can go back to v0.51.0.

[peterdemartini]

LGTM