revise fields in new member form [2]

[aguestuser]

Acceptance Criteria

[STUB] GIVEN I am the organizer of group foo with id 1 and I am visiting the new members page at groups/1/members/new

• THEN: i should see the same (?) fields as I see on the subgroup signup form AND in particular, I should be required to enter a zip code

[aguestuser]

@Matt-Holland : the AC's above could shift. I drew these assuming we want to completely incorporate the feedback from the client we spoke with last week about the confusing mismatch between the two kinds of new member forms we currently support.

we could also envision this being a custom form with different configurations for different groups?

or....?