plugin builder should support reexecute_on for task

[Aleksey Kasatkin]

Version: 8.0

reexecute_on field (sequence) was added into task description here: https://blueprints.launchpad.net/fuel/+spec/redeploy-network-on-changes
It is required to add its support to plugin builder then.
Now the following value is supported:

reexecute_on:
    - deploy_changes

Such task will be re-executed when apply-changes action is requested (url: /clusters/<cluster_id>/changes/).

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/260205

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/260205
Committed: https://git.openstack.org/cgit/openstack/fuel-plugins/commit/?id=c41143cba25912e3fe232de3fa63ced06f601ca5
Submitter: Jenkins
Branch: master

commit c41143cba25912e3fe232de3fa63ced06f601ca5
Author: Andriy Popovych <email address hidden>
Date: Mon Dec 21 22:16:40 2015 +0200

    Add validation for 'reexecute_on' deployment task attribute

    In context of 'redeploy-network-on-changes' feature appeared new attribute
    called 'reexecute_on' for deployment task. This patch provides basic json
    schema validation for it.

    Change-Id: I7aa7b00893182288b7cb86bef74f893289396caa
    Closes-Bug: #1527624

[Olesia Tsvigun (otsvigun)]

Verified at Fuel ISO#507
VERSION:
  feature_groups:
    - mirantis
  production: "docker"
  release: "8.0"
  api: "1.0"
  build_number: "507"
  build_id: "507"
  fuel-nailgun_sha: "8e954abd70ef0083109f34289de2553dcda544d4"
  python-fuelclient_sha: "4f234669cfe88a9406f4e438b1e1f74f1ef484a5"
  fuel-agent_sha: "658be72c4b42d3e1436b86ac4567ab914bfb451b"
  fuel-nailgun-agent_sha: "b2bb466fd5bd92da614cdbd819d6999c510ebfb1"
  astute_sha: "b81577a5b7857c4be8748492bae1dec2fa89b446"
  fuel-library_sha: "ec7e212972ead554f21b52b9e165156665f659df"
  fuel-ostf_sha: "ab5fd151fc6c1aa0b35bc2023631b1f4836ecd61"
  fuel-mirror_sha: "351d568fa3b3e4dd062054b91d766aa54d379867"
  fuelmenu_sha: "234cb4cbb30fbd2df00f388c28f31606d9cae15f"
  shotgun_sha: "63645dea384a37dde5c01d4f8905566978e5d906"
  network-checker_sha: "a43cf96cd9532f10794dce736350bf5bed350e9d"
  fuel-upgrade_sha: "616a7490ec7199f69759e97e42f9b97dfc87e85b"
  fuelmain_sha: "94507c5e4dad6d8cfbd8f5d41aa8389d5335990a"