Install tempest-lib as part of install_tempest

This commit adds support to devstack to install the newly created
tempest-lib project.

Change-Id: Ifcf56639757ec4814dcd31f791931afe61f5a672
ceilometer compute agent not started correctly

command isn't properly parsed after switch to run_process. this
patch corrects the regression

Change-Id: Ib28d4bbf6f150854fc5aa04e3fa4eed92005ce19
Closes-Bug: #1370673
Merge "ceilometer compute agent not started correctly"
Merge "Install tempest-lib as part of install_tempest"
Merge branch 'master' of https://github.com/openstack-dev/devstack