Imports of release-notes command

PathSynopsis
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.
github.com/google/go-github/githubPackage github provides a client for using the GitHub API.
osPackage os provides a platform-independent interface to operating system functionality.