use docker image with bundler 1.14 for unit tests
use docker image with bundler 1.14 for unit tests

Signed-off-by: Gabriel Dumitrescu <ac98dc248ba95b80e235d49d71a9a50afc4ea93d@pivotal.io>

barthy1/bosh,barthy1/bosh,barthy1/bosh,barthy1/bosh