Update Makefile to force commands through bash (#972)
Update Makefile to force commands through bash (#972)

Signed-off-by: Christopher M. Luciano <6a3ee4b7e940bce72c1857de462f1d5fc92fcd3d@us.ibm.com>
Former-commit-id: c36819c934053d70b3d061e52c57a930933a0b7e
mandarjog/istio,sebastienvas/istio,mandarjog/istio,sebastienvas/istio,istio/istio,mandarjog/istio,geeknoid/istio,frankbu/istio,istio/istio,smawson/istio,frankbu/istio,smawson/istio,smawson/istio,geeknoid/istio,smawson/istio,geeknoid/istio,frankbu/istio,sebastienvas/istio,mandarjog/istio,frankbu/istio,smawson/istio,istio/istio,istio/istio,frankbu/istio,geeknoid/istio,mandarjog/istio,smawson/istio,istio/istio,sebastienvas/istio,geeknoid/istio,geeknoid/istio,frankbu/istio,sebastienvas/istio