bump lager
bump lager

[finishes #162080538](https://www.pivotaltracker.com/story/show/162080538)

Submodule src/code.cloudfoundry.org/lager dcdeae45..baf208c4:
  > Write trailing new line for message consistency
  > Do not return empty entry when no bytes are read

Signed-off-by: Sunjay Bhatia <df2d57be7987a471915f625a5499155bc16d4200@pivotal.io>

cloudfoundry-incubator/diego-release,cloudfoundry-incubator/diego-release,cloudfoundry-incubator/diego-release,cloudfoundry-incubator/diego-release