Added new security question to sign up, Added notification for unconfirmed emails

• Added:
- new security question to sign up
- notification for unconfirmed emails
- modal for describing issue with Gab emails

app/models/user.rb

@@ -253,6 +253,10 @@ class User < ApplicationRecord
     @invite_code = code
   end
 
+  def challenge
+    # 
+  end
+
   def password_required?
     return false if Devise.pam_authentication || Devise.ldap_authentication
     super