[RFE] go install command name to be shamir or go-shamir instead of cli

[dougnukem]

Current situation

Running:

$ go install github.com/kinvolk/go-shamir/cli@latest
$ cli --help
Usage:
  shamir [command]

Available Commands:
  combine     Reconstruct a secret from the parts read from stdin
  help        Help about any command
  split       Split an arbitrarily long secret from stdin

Flags:
  -h, --help   help for shamir

Use "shamir [command] --help" for more information about a command.

installs the command to $GOPATH/bin/cli

Impact

Executing the command from $GOPATH/bin/cli is ambiguous.

Ideal future situation

Ideally you'd be able to install the command as shamir or go-shamir command.

**Implementation options

$ go install github.com/kinvolk/go-shamir/cli/shamir@latest
$ shamir --help
Usage:
  shamir [command]
...

Or even more simply just put the main.go in the repository root.

$ go install github.com/kinvolk/go-shamir@latest
$ go-shamir --help
Usage:
  go-shamir [command]
...