Override yum provider core plugin for puppet

Ensures yum provider would have expired cache
and redo last, if operation had failed

Signed-off-by: Bogdan Dobrelya <bogdando@mail.ru>
Add yumhelper.py

Signed-off-by: Bogdan Dobrelya <bogdando@mail.ru>
Merge branch 'feat_yumproviderretry'