Remove generate-cf-certs.sh
Remove generate-cf-certs.sh

This is no longer used now that the certs have been moved to the BOSH
vars store. Generation happens in `bosh interpolate` and rotation
happens in `rotate-cf-certs.rb`.

alphagov/paas-cf,alphagov/paas-cf,alphagov/paas-cf,alphagov/paas-cf,alphagov/paas-cf,alphagov/paas-cf,alphagov/paas-cf,alphagov/paas-cf