Add bbl tests for failure cases
Add bbl tests for failure cases

- add failure cases for create-lbs
- add failure cases for update-lbs

[#119210765]

Signed-off-by: Christian Ang <15ae83feccf4d84083a62aba1cdf46bd8ce2e33b@pivotal.io>

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