[#119843419] - add integration test verifying existing hooks are backedup
[#119843419] - add integration test verifying existing hooks are backedup

Signed-off-by: Jesse Malone <c929decda31f28e677c5c623b33cb23472ce0fde@pivotal.io>

pivotal-sprout/sprout-git,pivotal-sprout/sprout-git,pivotal-sprout/sprout-git