Fixes Google OpenID Connect

[fredericcambon]

This PR fixes the google openid connect (#494, #477 for more information)

It is my first contribution to this repo, could you ensure everything is in order?

[tonylampada]

Following this. Hope it works out.

[tonylampada]

I can confirm that it's possible to login using google-openidconnect with this patch.

The changes I had to do in my django application are here [1]
Also I had to create a project with a clientid/secret as instructed here [2]
Important: Authentication only worked after I enabled the "Google +" API for that project

[1] freedomsponsors/www.freedomsponsors.org@e45f986
[2] https://developers.google.com/accounts/docs/OpenIDConnect

The problem now is that, if I try to login on "/login/google-openidconnect", it will create a new User instead of authenticating into the previously existing one. Is there an easy solution for this problem?

/cc @omab - perhaps you can give me a pointer here too?

[tonylampada]

OK, no need. Just had to rtfm and use Associate Users by email.

Just for the record here's the relevant changes

[omab]

Closing, very broken tests.

[abompard]

Google says basic OpenID will stop working in 12 days, is there a way to auth with Google without requesting an API key from them?