[ENG] Add Marketing email opt-in to welcome page
Design Issue: gitlab-org/growth/team-tasks#162 (closed)
Requirements
- Remove marketing email opt in from registration page
- Only ask the user to opt into marketing emails if they select "Only me" when answering "Who will be using GitLab?" on the welcome page.
- Users selecting "My company or Team" should be opted into marketing mail in Marketo.
Edited by Nicolas Dular