This needs to deal with null dates, if start date and end data aren't required when defining a program. Otherwise I get 

    Express
    500 Template render error: (/Users/mlarsson/Work/checkouts/openbadger/views/admin/create-or-edit-issuer.html) Template render error: TypeError: Object has no method 'toISOString'

trying to edit a program for which I didn't choose dates.