Check correctly arguments
Check correctly arguments

It fixes argument parsing and verifies all mandatory arguments are
provided. It also prevents UnboundLocalError exceptions.

Change-Id: Iec3403533b312c95dd453236ccadb1fe495d61cd
Signed-off-by: Cédric Ollivier <d48310251a4a484d041bc5d09a9ac4d86d20f793@orange.com>

opnfv/functest,opnfv/functest,mywulin/functest,mywulin/functest