Imports of package testing

PathSynopsis
errorsPackage errors implements functions to manipulate errors.
fmtPackage fmt implements formatted I/O with functions analogous to C's printf and scanf.
github.com/Microsoft/hcsshim/hcnPackage hcn is a shim for the Host Compute Networking (HCN) service, which manages networking for Windows Server containers and Hyper-V containers.