[ci][10.0.all] Switch to Ubuntu Xenial repositories

[Ivan Udovichenko]

Please switch 10.0.all Jenkins job [1] to use Ubuntu Xenial [2] repositories instead of Ubuntu Trusty's one [3].
Currently in job parameters we may observe 'MOS_UBUNTU_ROOT=/mos-repos/ubuntu/':
https://product-ci.infra.mirantis.net/view/10.0/job/10.0.all/480/parameters/

Thank you.

[1] https://product-ci.infra.mirantis.net/view/10.0/job/10.0.all/
[2] http://mirror.fuel-infra.org/mos-repos/xenial/
[3] http://mirror.fuel-infra.org/mos-repos/ubuntu/

[Fuel Devops McRobotson (fuel-devops-robot)]

Fix proposed to branch: master
Change author: Alexander Evseev <email address hidden>
Review: https://review.fuel-infra.org/23266

[Fuel Devops McRobotson (fuel-devops-robot)]

Reviewed: https://review.fuel-infra.org/23266
Submitter: Aleksandra Fedorova <email address hidden>
Branch: master

Commit: 623e88f608969b04a83c30b7937c210ab90afaf7
Author: Alexander Evseev <email address hidden>
Date: Thu Jul 14 15:31:03 2016

[product-ci] Use Xenial repositories for MOS 10.0

Packages for Ubuntu Xenial are placed in dedicated path, so it's need
to reconfigure jobs to use it.

Change-Id: Ic9a5c0369e8e2b66b572e07c71f0a96e7c91b812
Closes-Bug: #1603128