Add Flow step to pipeline.yml

[AlexMSmithCA]

Created with fusion-orchestrate.

[AlexMSmithCA]

Update:

• Some minor Flow annotation changes to fix check complaints.
• Using comment-syntax here to avoid breaking tests - which don't appear to transform away Flow syntax

[KevinGrandon]

Looks good, but not sure if we want to use comment syntax? What unit tests were failing, shouldn't they be run through babel?

[rtsao]

!merge