Imports of authtest command

PathSynopsis
bufioPackage bufio implements buffered I/O. It wraps an io.Reader or io.Writer object, creating another object (Reader or Writer) that also implements the interface but provides buffering and some help for textual I/O.
bytesPackage bytes implements functions for the manipulation of byte slices.
flagPackage flag implements command-line flag parsing.
fmtPackage fmt implements formatted I/O with functions analogous to C's printf and scanf.
golang.org/x/sys/execabsPackage execabs is a drop-in replacement for os/exec that requires PATH lookups to find absolute paths.
ioPackage io provides basic interfaces to I/O primitives.
logPackage log implements a simple logging package.
net/httpPackage http provides HTTP client and server implementations.
net/textprotoPackage textproto implements generic support for text-based request/response protocols in the style of HTTP, NNTP, and SMTP.
net/urlPackage url parses URLs and implements query escaping.
osPackage os provides a platform-independent interface to operating system functionality.
path/filepathPackage filepath implements utility routines for manipulating filename paths in a way compatible with the target operating system-defined file paths.
stringsPackage strings implements simple functions to manipulate UTF-8 encoded strings.