verify-fuel-library-tasks should contain skipped type

[Matthew Mosesohn]

https://ci.fuel-infra.org/job/verify-fuel-library-tasks/6369/console fails to validate "skipped" task type to use as a placeholder anchor for the new granular neutron tasks.

tasks-validator should be updated to match the type of tasks supported by nailgun.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/241181

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/241181
Committed: https://git.openstack.org/cgit/openstack/fuel-library/commit/?id=c59c5500beca41c5f5de307c62e996562781ca9c
Submitter: Jenkins
Branch: master

commit c59c5500beca41c5f5de307c62e996562781ca9c
Author: Matthew Mosesohn <email address hidden>
Date: Tue Nov 3 15:24:06 2015 +0300

    Update task types to current nailgun task schema

    Added skipped and reboot task types to tasklib schema
    to match what is valid for Fuel 7.0 and 8.0. The schemas
    are the same for both releases, and as such, they have been
    added as new schema types for tasklib.

    Change-Id: Iace451be899b7aa10534502a003e2085e0ac16ae
    Closes-Bug: #1512639