Fix CF destroy by unpacking certificates for tf
Fix CF destroy by unpacking certificates for tf

This appears to have been broken since we added ELB's with certificates
on them for metrics etc, but nobody noticed as we rarely totally destroy
cf environments.

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