Improve Robustness of WskRestBasicUsageTests

[mhenke1]

Description

This PR changes the result comparison of two testcases to comparing sets instead of JsArrays.
This is introduced by seeing unstable results in some environments.

Related issue and scope

• I opened an issue to propose and discuss this change (#????)

My changes affect the following components

• API
• Controller
• Message Bus (e.g., Kafka)
• Loadbalancer
• Invoker
• Intrinsic actions (e.g., sequences, conductors)
• Data stores (e.g., CouchDB)
• Tests
• Deployment
• CLI
• General tooling
• Documentation

Types of changes

• Bug fix (generally a non-breaking change which closes an issue).
• Enhancement or new feature (adds new functionality).
• Breaking change (a bug fix or enhancement which changes existing behavior).

Checklist:

• I signed an Apache CLA.
• I reviewed the style guides and followed the recommendations (Travis CI will check :).
• I added tests to cover my changes.
• My changes require further changes to the documentation.
• I updated the documentation where necessary.

[markusthoemmes]

FWIW, if the sequence of these seems to matter in tests, we should make them not matter (by converting to a Set first).

[mhenke1]

@markusthoemmes I observed some weird parameter sequence related problems on my local system that should have concluded that the original Travis test should never have been successful. But it is of course better to prevent such problems instead of being hit by them at unforeseen times.

[sven-lange-last]

Thanks for making this more robust. You followed @markusthoemmes proposal to transform the array to a set to perform the comparison independent from the element order.

Changes look good to me. Merging.