Feature/remove user/soft removal

[OhMaley]

A brief description of the purpose of the changes contained in this PR.

This implement a full process to allow user's to remove their account automatically.
It includes:

• A new 'account view'
• A 'deletion account' section in it
• A delete confirmation pop-up with some verification
• An email confirmation message with a deletion link
• An email with a summary and details about the removed user
• The deletion of the user's personal attribute (or its anonymization)
• An email to the removed user to confirm its removal
• A modification on the login mechanism to not allow removed user's credentials

Issues this PR resolves

#1159

A checklist for hand testing

• Create a new user
• Complete its profile with as much information as possible
• Create an organization
• Create a competition
• Create a Queue
• Add a submission
• Make the competition and the submission public
• Log out and log in with another user
• Take a look at the new user profile
• Log out and log in with the new user's account
• Delete the account using the account view
• Check your email (or the message in the console)
• Click on the given link
• Check that admins received an email with information on the user's deletion
• Check the the deleted user's got a confirmation email
• Try to log in with the deleted user's account. And fail
• Log in as another user
• Check that the competition and submissions of the removed user are still here but without personal data
• Take a look at the removed user's profile and check that no personal information is displayed

Checklist

• Code review by me
• Hand tested by me
• I'm proud of my work
• Code review by reviewer
• Hand tested by reviewer
• CircleCi tests are passing
• Ready to merge

[Didayolo]

Question: is deleting from Django admin the same than deleting from "Account" drop down button?
(not very important anyway)

[OhMaley]

Question: is deleting from Django admin the same than deleting from "Account" drop down button? (not very important anyway)

No. Removing the Django admin only remove / anonymize the user personal data. It is only one of the step involved in the whole process. But note that is does not remove the user completly, it soft removes it.

Also I'll do some changes to include the email sent to the admins and the confirmation email sent to the user for all cases.

[Didayolo]

@OhMaley

Also I'll do some changes to include the email sent to the admins and the confirmation email sent to the user for all cases.

Should I wait for a commit from you before reviewing this PR then? Or is it already ready?

[OhMaley]

@OhMaley

Also I'll do some changes to include the email sent to the admins and the confirmation email sent to the user for all cases.

Should I wait for a commit from you before reviewing this PR then? Or is it already ready?

Yes, wait for my modifications You will be able to review this PR after my next push