A new router is created in every network creation

[jorgesece]

Every time that we create a new network by using neutron, OOI creates a new router and links it to the public network. Since, the public network pool has limited ip addresses, it is better to use one of the existing routers which is already linked to the public network.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/391494

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/391494
Committed: https://git.openstack.org/cgit/openstack/ooi/commit/?id=e2207d7c1268e35244adf0c2241fea2453976b17
Submitter: Jenkins
Branch: master

commit e2207d7c1268e35244adf0c2241fea2453976b17
Author: jorgesece <email address hidden>
Date: Fri Oct 28 14:50:57 2016 +0100

    Check if router exists on network creation

    List the routers of the tenant and use the first router with external
    gateway, thus It is linked to the public network.
    In case no router with those features is found, a new one is created.

    Change-Id: I696ebe04426fab7e210d86f30084c4fee64cbce8
    Closes-bug: #1637497