global: handle termination signals

[diegodelemos]

• Uses REANA-Commons decorator to handle termination signals in the workflow engine container by notifying the system about the failure and registering the workflow as failed.

Addresses reanahub/reana#478

[codecov-io]

Codecov Report

Merging #132 (ae20fb1) into maint-0.7 (5eef130) will increase coverage by 3.09%. The diff coverage is 0.00%.

@@              Coverage Diff              @@
##           maint-0.7     #132      +/-   ##
=============================================
+ Coverage      24.71%   27.81%   +3.09%     
=============================================
  Files              5        5              
  Lines            178      151      -27     
=============================================
- Hits              44       42       -2     
+ Misses           134      109      -25     

Impacted Files	Coverage Δ
reana_workflow_engine_serial/tasks.py	0.00% <0.00%> (ø)
reana_workflow_engine_serial/utils.py	35.80% <ø> (-0.67%)	:arrow_down: