Use email not username for login

[4lm]

While working on #188, I got annoyed by having to use my username as my login name (I typed my email multiple times in because I'm so used to doing so). Most websites demand the email or give you the option to use email or username as a login name.

@Bachibouzouk, is It OK for you if I change this to demanding the email address instead of the user name?

[Bachibouzouk]

I think few people would remember their usernames anyway, maybe I am the only one using username with test user. I think we should leave the possibility to log in with the user name, just not make it the default one

[4lm]

I think few people would remember their usernames anyway, maybe I am the only one using username with test user. I think we should leave the possibility to log in with the user name, just not make it the default one

This might be more challenging than it seems at first glance. I looked at the implementation of AbstractUser. I discovered that a user could generate a username that looks like an email. Therefore, even if we fix #191, the system cannot determine if an input is a username or email in some instances. because usernames can have an email-like shape "Letters, digits and @/./+/-/_ only." Yes, of course, we could have two input fields, one for email and one for username, but this is atypical and adds friction.

Therefore I vote for either username or email. And also vote for leaving it like this for now (username) because we have more important fish to fry.

@Bachibouzouk, what do you think?

[Bachibouzouk]

Leave it as is then @4lm :) Agreed