Make required changes for paywall<->app communication

[cnasc]

Making an issue for these so I can make sure I get them all

• [ ] postOfficeMiddleware needs to respond to LockUpdate, not KeyPurchase

  postOfficeService.on(PostOfficeEvents.LockUpdate, locks => {
  const lock = Object.values(locks)[0] // probably not exactly this?
  dispatch(addToCart({ lock }))
  })

• [x] storageMiddleware needs to dispatch keyPurchaseInitated after success.keyPurchase

  storageService.on(success.keyPurchase, () => {
  dispatch(keyPurchaseInitiated())
  })

• [x] storageMiddleware needs to fetch cards from locksmith when a new payment method is added

  storageService.on(success.addPaymentMethod, ({ emailAddress }) => {
  storageService.getCards(emailAddress)
  })

[cellog]

Making an issue for these so I can make sure I get them all

• [x] postOfficeMiddleware needs to respond to LockUpdate, not KeyPurchase

 postOfficeService.on(PostOfficeEvents.LockUpdate, locks => {
  const lock = Object.values(locks)[0] // probably not exactly this?
  dispatch(addToCart({ lock }))
})

So this is not correct. It needs to save all of the locks it gets into the store. We could receive a key purchase request on any of them