Update bosh-go CLI and reduce docker layers
Update bosh-go CLI and reduce docker layers

- new bosh-go CLI need for the CI
- reducing the docker layers improves a little bit
  the build performance and cache behavior. When
  `apt-get update` has it's own docker layer it is cached
  by docker and layers which are following and installing things
  get the old cached content of `apt-get update`

[#144509311](https://www.pivotaltracker.com/story/show/144509311)

Signed-off-by: Beyhan Veli <0702de361e3c91d973ce2c0ee3e34845ebaf95e6@sap.com>

cloudfoundry-incubator/bosh-openstack-cpi-release,cloudfoundry-incubator/bosh-openstack-cpi-release,cloudfoundry-incubator/bosh-openstack-cpi-release