Imports of jwt command

PathSynopsis
encoding/jsonPackage json implements encoding and decoding of JSON as defined in RFC 7159.
flagPackage flag implements command-line flag parsing.
fmtPackage fmt implements formatted I/O with functions analogous to C's printf and scanf.
github.com/dgrijalva/jwt-goPackage jwt is a Go implementation of JSON Web Tokens: http://self-issued.info/docs/draft-jones-json-web-token.html
ioPackage io provides basic interfaces to I/O primitives.
io/ioutilPackage ioutil implements some I/O utility functions.
osPackage os provides a platform-independent interface to operating system functionality.
regexpPackage regexp implements regular expression search.