Return Unimplemented for ResourceRequirement

[anton-khodak]

Related issues: reanahub/reana-job-controller#32, reanahub/reana-job-controller#31

[mr-c]

Reason: reana-cwl-runner currently has no way to verify that the resources required are available on the assigned machine nor does it have the ability to request from REANA certain minimum machine resources (CPU cores, memory, storage space, etc..)

[tiborsimko]

Moving the milestone as the CWL test suite passes fully:

...
Test [125/128] Test simple workflow with a dynamic resource requirement
Test [126/128] Test that empty array input does not add anything to command line
Test [127/128] Test that ResourceRequirement on a step level redefines requirement on the workflow level
Test [128/128] Test valueFrom with constant value overriding provided array inputs
All tests passed

All tool tests succeeded