Fix wasmer publish not bumping versions for named packages

[syrusakbary]

Basically, two behaviors in a named package, that is versioned:

• Package & version exists in the Registry
  • If in interactive mode: ask to the user if they want to bump the version (and prompt the version, so they can change it… although the default is an increase in the patch version)
  • If in non interactive mode:
    • If --bump is present, then one of the values are --bump=major/minor/patch
    • If --bump is not present: FAIL with a nice error message
• Package & version don't exists in the Registry
  • Normal Publish flow