feat(dask): dask autoscaler config (#604)

[Alputer]

closes reanahub/reana#834

[codecov]

Codecov Report

Attention: Patch coverage is 76.31579% with 54 lines in your changes missing coverage. Please review.

Project coverage is 75.71%. Comparing base (e36c6a2) to head (ac5573d).

Files with missing lines	Patch %	Lines
reana_workflow_controller/dask.py	77.32%	39 Missing ⚠️
reana_workflow_controller/k8s.py	20.00%	8 Missing ⚠️
reana_workflow_controller/consumer.py	50.00%	4 Missing ⚠️
reana_workflow_controller/workflow_run_manager.py	57.14%	3 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #604      +/-   ##
==========================================
+ Coverage   75.59%   75.71%   +0.12%     
==========================================
  Files          15       16       +1     
  Lines        1565     1791     +226     
==========================================
+ Hits         1183     1356     +173     
- Misses        382      435      +53     

Files with missing lines	Coverage Δ
reana_workflow_controller/config.py	93.23% <100.00%> (+2.05%)	⬆️
reana_workflow_controller/workflow_run_manager.py	80.67% <57.14%> (-0.45%)	⬇️
reana_workflow_controller/consumer.py	55.27% <50.00%> (-0.28%)	⬇️
reana_workflow_controller/k8s.py	83.82% <20.00%> (-5.07%)	⬇️
reana_workflow_controller/dask.py	77.32% <77.32%> (ø)