New spec

[Qix-]

This is a refactor of the spec definitions as discussed internally.

Note the new usage: https://github.com/zeit/zarg/blob/e09f1d5b111dc55efd15d80783ca2f55f59205f2/README.md#usage

[leo]

We don't need the dashes on the main object argument:

{
  '--version': Boolean,
  '-v': '--version'
}

Should become:

{
  version: Boolean,
  v: 'version'
}

As a result, we need to just test if the option name has a .length of 1 (short flag) or more (normal flag) - no dashes needed.

[Qix-]

@leo Disagree after a bit of usage.

For example, when I needed to debug the --token problem in now-cli, searching for --token only showed the help text, and token by itself showed just about every file in the client.

While you're not necessarily wrong, a bit of explicitness is fine in this case.