tripleo-quickstart creating redundant repositories

Quickstart creates additional yum repository files [0] which point to the same online repository with a name that matches case insensitively [1]. Even if the redundant repositories are disabled, attempts to install packages from these repositories result in the package not being found and warning:

 Repository $FOO is listed more than once in the configuration

This was seen recently in TripleO CI [2][3][4][5] and can be reproduced
by setting up the same files in /etc/yum.repos.d and attempting to install
a package found in both the enabled an disabled repository.

[0] https://github.com/openstack/tripleo-quickstart/blob/master/config/release/tripleo-ci/consistent-master.yml#L38-L79

[1]
[root@4ed2422bb531 yum.repos.d]# ls | sort -f
CentOS-Base.repo
centos-base.repo
CentOS-Ceph-Jewel.repo
centos-ceph-jewel.repo
CentOS-CR.repo
CentOS-Debuginfo.repo
centos-extras.repo
CentOS-fasttrack.repo
CentOS-Media.repo
centos-opstools.repo
centos-qemu.repo
CentOS-Sources.repo
centos-updates.repo
CentOS-Vault.repo
delorean-current.repo
delorean-pike-testing.repo
delorean.repo
gating.repo
[root@4ed2422bb531 yum.repos.d]#

[2]
[root@4ed2422bb531 ~]# yum install ceph-ansible
Loaded plugins: fastestmirror, ovl
Repository centos-ceph-jewel is listed more than once in the configuration
Loading mirror speeds from cached hostfile
No package ceph-ansible available.
Error: Nothing to do
[root@4ed2422bb531 ~]#

[3] http://logs.openstack.org/88/479288/32/check/gate-tripleo-ci-centos-7-scenario001-multinode-oooq-container/2dd0e52/logs/undercloud/etc/yum.repos.d/

[4] http://logs.openstack.org/88/479288/32/check/gate-tripleo-ci-centos-7-scenario001-multinode-oooq-container/2dd0e52/logs/undercloud/etc/yum.repos.d/CentOS-Ceph-Jewel.repo.txt.gz

[5] http://logs.openstack.org/88/479288/32/check/gate-tripleo-ci-centos-7-scenario001-multinode-oooq-container/2dd0e52/logs/undercloud/etc/yum.repos.d/centos-ceph-jewel.repo.txt.gz