Fix go authors assignment

[isi-lincoln]

rvn@moa:~$ go get -u github.com/hasit/bolter
# github.com/hasit/bolter
go/src/github.com/hasit/bolter/bolter.go:43:14: cannot use []cli.Author literal (type []cli.Author) as type []*cli.Author in assignment
rvn@moa:~$ go install github.com/hasit/bolter
# github.com/hasit/bolter
go/src/github.com/hasit/bolter/bolter.go:43:14: cannot use []cli.Author literal (type []cli.Author) as type []*cli.Author in assignment

After applying this MR:

rvn@moa:~$ go install github.com/hasit/bolter
rvn@moa:~$ ~/go/bin/bolter 
NAME:
  bolter - view boltdb file interactively in your terminal

VERSION:
  2.0.1

USAGE:
  bolter [global options]

GLOBAL OPTIONS:
  --file FILE    boltdb FILE to view
  --help, -h     show help (default: false)
  --version, -v  print the version (default: false)
  
AUTHOR:
  Hasit Mistry <[email protected]>
COPYRIGHT:
  (c) 2016 Hasit Mistry

Go Version (installed from apt package): go version go1.15.15 linux/amd64