Bump Java buildpack

git shortlog 01a6668..e461eeb

  Bleicke and Jennifer Hickey (1):
    Support Play 2.1 Apps

  David Sabeti and Jennifer Hickey (2):
    More robust checking for Play app directory
    Allow opt-out of spring auto-reconfiguration via
      system.properties file

  Max Brunsfeld (1):
    Recreate fake jdk tar to try to fix travis