🐛 `cpac --version` does not return version

[shnizzedy]

Describe the bug

Additionally cpac --version does not return version, but rather returns the whole help documentation for cpac. Same as cpac --help, although cpac run --version does give version number.

― https://github.com/FCP-INDI/cpac/issues/21#issue-1069646705

To reproduce

1. Run cpac --version
2. See usage information

Expected behavior

cpac --version returns version information

Acceptance criteria

• [x] cpac --version returns the version of cpac

Screenshots

No response

C-PAC version

No response

Container platform

No response

Docker and/or Singularity version(s)

No response

Additional context

cpac version 0.4.0

[shnizzedy]

Resolved in #29