This also adds a 500 response with the old key if the API key
refresh was unsuccessful. Previously, if the key refresh was
unsuccessful, this would result in an UnhandledPromiseRejection.
This is a new interface.
Signed-off-by: Christina Ying Wang <christina@balena.io>
This excludes route tests or refactoring. Also, created tests
for API middleware.
Change-type: patch
Signed-off-by: Christina Ying Wang <christina@balena.io>