subkey doesn't show version (--version dosn't work anymore)

[alvicsam]

After 511e8c8 subkey --version doesn't work (there is no such option anymore):

$ subkey -h
subkey
Parity Team <[email protected]>
Utility for generating and restoring with Substrate keys

USAGE:
    subkey <SUBCOMMAND>

OPTIONS:
    -h, --help    Print help information

SUBCOMMANDS:
    generate             Generate a random account
    generate-node-key    Generate a random node libp2p key, save it to file or print it to
                         stdout and print its peer ID to stderr
    help                 Print this message or the help of the given subcommand(s)
    inspect              Gets a public key and a SS58 address from the provided Secret URI
    inspect-node-key     Print the peer ID corresponding to the node key in the given file
    sign                 Sign a message, with a given (secret) key
    vanity               Generate a seed that provides a vanity address
    verify               Verify a signature for a message, provided on STDIN, with a given

This breaks master pipeline (job build-linux-subkey). I'll fix this job but it would be nice to return that option back.