Improve error handling

[krzkaczor]

• error messages should be visually distinctive (for example red)
• In some cases error messages could be clearer:
  • ny test when executed not in js repo returns: "Error: Couldn't find any lockfile inside dir or any of its parents.". Probably it should say that "test" was treated as task name and there is no javascript project.
  • ny not-existing-task" returns:
• Error can we swollen if PM throws an error (for example because version requirements are not meet (engine package.json field)