Add core code

[alejandromumo]

• Base repo structure updated:
  • Added black formatter, isort and pydocstyle
  • Added pytest and tests/ folder
  • Added db class to manage db (session and engine)
  • Added base Logger class
  • Added custom errors to start with.
• Added init command
  • Creates the a lycophron.cfg file with required configurations to run a project.
  • Creates a local database.
• Added load command
  • Reads a .csv file and processes it using marshmallow.
  • Dumps the read data in to the local database.
• Added publish command
  • Reads records from the local database and published to Zenodo.
  • Implemented using celery in multiple steps:
  • Spawns a base celery task that will run all the steps.
  • After creating a deposition, every file of a record is uploaded in parallel using a group.
  • When files group task is ready, a new task is linked to publish the record. See celery docs for more details on this approach.

Example of a record uploaded with lycophron: https://sandbox.zenodo.org/record/1159642

Notes:

• Only records with DOI are accepted for now.
• Empty values on a record's field (e.g. keywords) are stripped and considered to be non-existent.