Redirect data to new backoffice - add feature flag

[karolina-siemieniuk-morawska]

TECH NOTES:

• Create an Bearer token in backfofifce for creating workflows
• Update k8s with the token in hep BACKOFFICE_BEARER_TOKEN
• Refactor this function to accept a url and token a parameter instead of having only next hardcoded
• Refactor the code if needed to use the new function
• Add a feature flag [here (https://github.com/inspirehep/inspirehep/blob/master/backend/inspirehep/submissions/views.py#L194) FEATURE_FLAG_ENABLE_SEND_TO_BACKOFFICE and send also to the new backoffice (using the function).

[drjova]

Test in QA that submissions are going to backoffice as well (i.e. FEATURE FLAG, TOKEN etc)