Update certs expiration date

Update certs expiration date

PROBLEM: By default certs were generated with 30 days of
expiration days from image build date. When no new releases
were made during that time certs were loosing validity and
caused problems.

SOLUTION: Updated generation process to set 730 days (2 years)
until expiration date for new certs.
Updated subject of new certs.

Change-Id: I933cbbd1f80d824913cddbe19fc65988643d2282
Signed-off-by: Michal Banka <michal.banka@nokia.com>
Issue-ID: VNFSDK-650