Tempest does not requires DB devel libs

DB devel libs not used by tempest since havana.

Change-Id: Ia8c16a4a5a48e48e1bf916ca577385b2d1dd778f
removing the orphaned os_concat function

os_concat function not used anywhere in puppet-tempest.

Change-Id: I349b15edb669e9655a773ebb537cfbbd96b91e20