This patch moves (re,un)install commands for Tempest from "tempest"
category to "verify" category. Now to (re,un)install Tempest we can
execute the following commands:
$ rally verify install
$ rally verify uninstall
$ rally verify reinstall
In addition, missing unit tests were added. The corresponding changes
were made in rally-verify.sh script to pass Jenkins check.
Implements: blueprint improve-tempest-manage-cli
Change-Id: Ibe6713b755982acf1f7e4b89b13fd2a0dad7c034