Fix payments for MIVS groups Fixes https://jira.magfest.net/browse/MAGDEV-1022. We were inadvertently sending Stripe a list instead of a string object, but only for MIVS groups (most models have just a single email address).
Fix payments for MIVS groups
Fixes https://jira.magfest.net/browse/MAGDEV-1022. We were inadvertently sending Stripe a list instead of a string object, but only for MIVS groups (most models have just a single email address).

magfest/ubersystem,magfest/ubersystem,magfest/ubersystem,magfest/ubersystem