shoud add tempest-lib version dependency in requirements.txt

[yalei wang]

in tempest code, service_client.py depend on the common module in tempest_lib

2015-01-21 01:55:17.397 | File "/opt/stack/tempest/tempest/common/service_client.py", line 15, in <module>
2015-01-21 01:55:17.397 | from tempest_lib.common import rest_client

so, it's better to add the dependency in requirements.txt

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/148783

[OpenStack Infra (hudson-openstack)]

Change abandoned by yalei wang (<email address hidden>) on branch: master
Review: https://review.openstack.org/148783
Reason: make the dependency into global req, we can get it in this patch

https://review.openstack.org/#/c/148789/

[Ken'ichi Ohmichi (oomichi)]

https://review.openstack.org/#/c/148789/ has fixed this problem already.