Sklarsa Django Sendgrid V5 Versions Save

Fix #114

Adds attachment content-type method handling (#103) Adds configurable tracking per-email (#101)

Adds Django 3.2+ & 4.0 compatibility

Closes https://github.com/sklarsa/django-sendgrid-v5/issues/99

Personalization Fixes:

• _build_sg_personalization "to" arg now changed to optional; either it or existing_personalizations must be set.
• Prevent using .personalizations without tos set.
• Prevent unnecessary resetting of tos when personalization is already constructed.
• No longer provide tos if not set for personalizations. This is to prevent every personalization from being sent to every recipient in msg.to
• Added/Changed some comments/docstrings to reduce ambiguity

Thanks @alichass for the contribution!

Improves flexibility of personalizations by allowing the user to set the EmailMessage.personalizations attribute to a list of sendgrid Personalization objects, or a list of Dicts containing personalization information in the schema expected by the API. Personalization options passed this way take precedence over other EmailMessage attributes.

Breaking Changes

• Drops python 2 support

Improvements

• Adds type checking, linting, and code formatting
• Simplifies code where possible (no functionality changes)
• Adds github actions support
• Adds newer django versions to the testing matrix
• Improves documentation

Deprecations

• Removes TravisCI support
• Removes codecov uploads (coverage is still run in the tests)

Breaking Changes

• Drops python 2 support

Improvements

• Adds type checking, linting, and code formatting
• Simplifies code where possible (no functionality changes)
• Adds github actions support
• Adds newer django versions to the testing matrix
• Improves documentation

Deprecations

• Removes TravisCI support
• Removes codecov uploads (coverage is still run in the tests)

Thanks to @MattFanto for the PR and bug fix!

Now supports the newest version of sendgrid's api (https://github.com/sendgrid/sendgrid-python/releases/tag/v6.0.0). Maintains backwards compatibility.