Validation pipeline MVP: job to format the results of multiple validation jobs

[yannfeat]

Description

The last job of the the validation pipeline MVP's workflow, that will pull the results of all the validatoR jobs run on the target package and its dependencies (designed in #65), and then produce an overall validation report.

Tasks

• Write a JSON definition file
• Write a script that returns JSON files containing information on the validation status of each package (target and dependencies)
• Integrate the script in the pipeline

[Stefan-Doering-BI]

Created a PR (pharmaR/thevalidatoR#5), which adds the JSON Definition file.

[yannfeat]

See pharmaR/thevalidatoR#9