Remove sensitive temporary file on exit.
Remove sensitive temporary file on exit.

[#153851093]

Signed-off-by: Iain Sproat <98a867ba572e97ae83e7c3435e799fdacc1d61d0@pivotal.io>

pivotal-cf-experimental/kubo-deployment,jaimegag/kubo-deployment,jaimegag/kubo-deployment,pivotal-cf-experimental/kubo-deployment