Replace zap with zerolog.
zerolog has a cleaner interface and can be easily configured with custom
error chain printing using a new error handling library that will be
implemented in another PR.
Replace https://github.com/satori/go.uuid with maintained version at
https://github.com/gofrs/uuid
Since the new version uuid.NewV4 returns an error when failing to read
from the random source reader we use uuid.Must to panic on error since
it's considered an unrecoverable error.
In future, if needed, we could handle the error instead of panicking.
During tests provide a zaptest Logger so all services output will be redirected
to golang testing logger.
When multiple services of the same type are provided add a unique name field to
distinguish them.
Simone Gotti
alessandro.pinna