Preemptible instances are cheaper, and the small chanse of a vm being
killed doesn't matter when running during development. This is a
tradeoff the user should be able to decide on.
More info here:
https://cloud.google.com/compute/docs/instances/preemptible
The default setting is false, so unless setting
PREEMPTIBLE_INSTANCES=true, everything will behave as before.
Signed-off-by: Odin Ugedal <odin@ugedal.com>