Imports of package storage

PathSynopsis
contextPackage context defines the Context type, which carries deadlines, cancellation signals, and other request-scoped values across API boundaries and between processes.
errorsPackage errors implements functions to manipulate errors.
github.com/google/certificate-transparency-go/trillian/ctfe/configpb
github.com/google/certificate-transparency-go/trillian/ctfe/storage/mysqlPackage mysql defines the IssuanceChainStorage type, which implements IssuanceChainStorage interface with FindByKey and Add methods.
github.com/google/certificate-transparency-go/trillian/ctfe/storage/postgresqlPackage postgresql defines the IssuanceChainStorage type, which implements IssuanceChainStorage interface with FindByKey and Add methods.
stringsPackage strings implements simple functions to manipulate UTF-8 encoded strings.