FEATURE: Let users update their emails before confirming

This allows users who entered a typo or invalid email address when
signing up an opportunity to fix it and resending the confirmation
email to that address.

spec/fabricators/user_fabricator.rb

@@ -36,6 +36,7 @@ Fabricator(:inactive_user, from: :user) do
   name 'Inactive User'
   username 'inactive_user'
   email 'inactive@idontexist.com'
+  password 'qwerqwer123'
   active false
 end