deploy: Workaround for cert_override.txt

For cyclades, pithos, astakos, and cms use firefox_cert_override.py
script (credits to kpap@grnet.gr) to manually create proper entries
so that the end user running firefox does not have to accept all
certificates before having a working environment.

This will add /etc/iceweasel/profile/cert_override.txt on client
node with entries for:

astakos.synnefo.live:443
cyclades.synnefo.live:443
pithos.synnefo.live:443
cms.synnefo.live:443
synnefo.live:443

and the corresponding IPs (currently needed for cyclades UI).

For further info about cert_override.txt file see:

https://developer.mozilla.org/en-US/docs/Cert_override.txt

Signed-off-by: Dimitris Aragiorgis <dimara@grnet.gr>