Refactored create-lbs to use private functions
Refactored create-lbs to use private functions

- add checkFastFails function
- add updateStackAndBosh function

[#119210765]

Signed-off-by: Adrian Zankich <06c4bdd5da019c5d30546d0230d625621ed622b0@pivotal.io>

pivotal-cf-experimental/bosh-bootloader,niroyb/bosh-bootloader,pivotal-cf-experimental/bosh-bootloader,niroyb/bosh-bootloader