Comment 10 for bug 1508579

yum always installs fuel-library6.1 instead of fuel-library7.0 because a new dependency appeared: python-fuelclient [1]

So it seems:
   Since both fuel-library6.1 and fuel-library7.0 provides the same package: `fuel-library` yum select those which has less dependencies [2]

To check, I've created pathset [3] which removes python-fuelclient and add the resulted repo [4]. As the result the correct version of the package was installed [5]. So to resolve current issue we need to use fuel-library7.0 explicitly

[1]. https://github.com/openstack/fuel-library/blob/stable/7.0/specs/fuel-library7.0.spec#L17
[2]. http://paste.openstack.org/show/477331/
[3]. https://review.openstack.org/#/c/239190/
[4]. http://perestroika-repo-tst.infra.mirantis.net/review/CR-239190/mos-repos/centos/mos7.0-centos6-fuel/proposed/x86_64/
[5]. http://paste.openstack.org/show/477332/
[6]. https://github.com/openstack/fuel-main/blob/stable/7.0/docker/fuel-centos-build/fuel-centos.ks#L75