Refactor Tempest installation directories structure

For each deployment Tempest should be installed in directory
"~/.rally/tempest/for-deployment-*deploy_id*".
Also tempest.conf should be stored in this directory.

blueprint tempest-verification

Change-Id: Ieb16e1e32599ee3f3041f04c6ab31f4013d44590
Merge "Refactor Tempest installation directories structure"