feat(version): use exit code for check to indicate out-of-date versions

It can be handy to have an exit code that allows better status
indication or chaining.

On exit, return one of the following codes:

- 0: Normal exit condition, all checked versions are up-to-date
- 1: Unknown cause of failure
- 2: Normal exit condition, but there are out-of-date versions
- 3: Failed to run some version checks

Component: pkgctl version check
Signed-off-by: Levente Polyak <anthraxx@archlinux.org>

0 files changed, 0 insertions, 0 deletions