Extend django-dbbackup to backup s3 data to DropBox

• Django >=3.2, <4.0

1. Create a new virtualenv and activate it
2. Install the packages - pip install -r requirements.txt -U and add storage_sync to INSTALLED_APPS in Django settings.
3. Make sure you have set the settings variables for django-storage packages
   1. AWS_ACCESS_KEY_ID
   2. AWS_SECRET_ACCESS_KEY
   3. AWS_STORAGE_BUCKET_NAME
   4. AWS_S3_REGION_NAME
   5. DROPBOX_OAUTH2_TOKEN
   6. DROPBOX_OAUTH2_REFRESH_TOKEN
   7. DROPBOX_APP_KEY
   8. DROPBOX_APP_SECRET
4. Set the values for the following variables in settings.py
   1. SYNC_S3_BUCKET - The name of the bucket to sync (default: settings.AWS_STORAGE_BUCKET_NAME)
   2. SYNC_S3_DIR - The directory in the bucket to sync (default: s3-source-dir/)
   3. SYNC_DROPBOX_DIR - The directory in the dropbox the backup to be uploaded (default: dropbox-dest-dir/)
   4. SYNC_TARGET_FILE_NAME - The custom name of the file to be uploaded (default: backup.tar.gz)
5. Run the management command - python manage.py s3backup (by default the management command will use the values defined in the settings.py. But, it can be overridden by passing commandline args)
   1. Run python manage.py s3backup --help to see all available options (incl. Compression of backup)

docker run -it --rm -v "$(pwd):/app" python:3.7 bash -c "cd /app; pip install -e .[tests]; pytest"