Add autocomplete="email" to email fields

[MikeRogers0]

I'd really like to add autocomplete="email" to fields where we've requested users emails such as:

• confirmations/new.html.erb
• registrations/new.html.erb
• sessions/new.html.erb
• unlocks/new.html.erb
• passwords/new.html.erb

This will autofill the email fields with an email address saved to the browser, but also encourage developers to look into other autofill options. What do you think? (If you like it, I'm happy to PR :) )

[rafaelfranca]

Please open the PR. Closing since this is a feature request. Thanks