Fix tests and provided_by

Note, that pcs_fincing rspecs could be run only after the
plugin have been built and dependent puppet modules
(corosync, stdlib) downloaded from Fuel by pre build hook

Change-Id: I505bee27a7886b28f0cf79490a32ac919ed9fc47
Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>