Make use of new maven plugin functionality

    Simplify the helloworld example build by using
    the artifactBundleType propery of the fabric8 plugin.

    This change should have been applied when
    the mule example was tidied. However, it
    seems to have got lost (perhaps due to a rebase?).

    What is interesting is that this change doesn't seem
    to necessary for the example to build correctly and work
    (it was verified several times during the 'tidy' merge).

    Previously it was not possible to apply the workaround
    (stopping artifact inclusion and manually specifying
    the bundle specifier as an additional bundle) could not
    be applied because the parent project would not respect
    these settings when applied to a child project. It
    is possible that some recent refactoring in the
    archetypes projects has made this possible.

    The new parameters are more intuitive than the previous
    work around. So it still makes sense to apply this change.