Update django-invitations to 1.9.1

[pyup-bot]

There's a new version of django-invitations available.
You are currently using 1.8. I have updated it to 1.9.1

These links might come in handy: PyPI | Changelog | Repo

Changelog

1.9

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• Added get_signup_redirect to allow custom implementations by subclasses

• Fixed invitation form displaying "None" when first displayed

• Fixed deprecation warnings

• Added get_signup_redirect to allow custom implementations by subclasses

• Fixed flake8 errors

• Import reverse from django.urls if available, otherwise fall back to old import

• Set ForeignKey field to explicitly cascade on deletion

• flake8 styling formatting

• Add email max length setting

Got merge conflicts? Close this PR and delete the branch. I'll create a new PR for you.

Happy merging! 🤖