Imports
- github.com/pkg/errors
- golang.org/x/net/context
- github.com/armon/go-metrics
- google.golang.org/api/option
- github.com/hashicorp/vault/helper/useragent
- google.golang.org/api/iterator
- github.com/hashicorp/errwrap
- google.golang.org/grpc/codes
- cloud.google.com/go/spanner
- github.com/hashicorp/go-uuid
- github.com/hashicorp/go-hclog
- github.com/hashicorp/vault/physical
- github.com/hashicorp/vault/helper/strutil