Add support for collapsible dropdown menus when they don't have any items.
Consolidate PremiumScheduleController and PremiumSchedulesController
Redirect from PremiumSchedulesController#edit if there is no repayment frequency
Prevent calculation of state aid, when a repayment frequency isn't set.
Don't allow "Legacy Monthly" to be selected as a RepaymentFrequency.
Merge pull request #154 from alphagov/fix-loan-repayment-frequency-exception

Fix Loan Repayment Frequency Exception