Send emails to console backend when developing locally

[jarifibrahim]

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• feature request
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When running the web app locally, new user registration will fail due to missing SMTP credentials.
Use https://docs.djangoproject.com/en/dev/topics/email/#console-backend as email backend when developing locally

[jarifibrahim]

This issue becomes obsolete with this PR #224

I'm closing this issue. We can reopen this when we add email related features.