ignore puppet temp files

TelekomLabs-DCO-1.1-Signed-off-by: Edmund Haselwanter <me@ehaselwanter.com> (github: ehaselwanter)
update rubocop

TelekomLabs-DCO-1.1-Signed-off-by: Edmund Haselwanter <me@ehaselwanter.com> (github: ehaselwanter)
use command instead of backend.run_command

TelekomLabs-DCO-1.1-Signed-off-by: Edmund Haselwanter <me@ehaselwanter.com> (github: ehaselwanter)
Merge pull request #8 from ehaselwanter/serverspec2-update

update to serverspec2