Imports
- github.com/giantswarm/cert-operator/flag
- github.com/giantswarm/certctl/service/pki
- github.com/giantswarm/certctl/service/token
- github.com/giantswarm/certificatetpr
- github.com/giantswarm/microkit/error
- github.com/giantswarm/microkit/logger
- github.com/hashicorp/vault/api
- github.com/juju/errgo
- github.com/spf13/viper