A collection MR of minor tweaks that I notice while developing but are out-of-scope

Changes

generate:migrate minor error code bug

!35 (919f3d9a)
The value for ret was defined in the wrong scope and therefore error codes risked being calculated incorreclty.

Remove redundant tck_id variable from hackily_change_dataPackages_cmd

!35 (fefb3e59)

• added minor docstring explaining

workflow_and_settings comparisons were somewhat clunky and duplicated

!35 (b08e2bc2)

Slimmed down now

Prevent typos or comparison to hard-coded strings by defining stack-based and commit-based workflow variables once

!35 (46b22a00)

No need to define subparser and then lambda to it -> Just define it within appropriate scope initially

!35 (40b88c76)

Large changes to use a class for Workflow(enum) and Specification

!35 (8b514816)

This reduces a lot of hard-coded tck_spec['parameters']['label'] etc, now it's defined once and only once, and all accessing of these variables henceforth are much nicer.

spec = helper.yaml_parser(yaml_fp)
tck_id = hex(spec['ID'])
tck_commits = spec['parameters']['commits']
...
# ->
spec = Spec(yaml_fp)
tck_id = spec.id
tck_commits = spec.commits
...

ToDo

• Verify if this is necessary anymore hackily_change_dataPackages. POSTPONED TO : #17 (closed)