chore(docker): add base ubuntu docker image for CI

related to #CAM-3195
chore(keys): add keys also as id_rsa ssh keys to users
chore(ubuntu): update ubuntu version to 14.04.1
chore(build): add DOCKER_OPTS to build script

- it allows to set general docker opts like the docker daemon ip:port                                              │Removing intermediate container 11b10955590c
  with `export DOCKER_OPTS=-H tcp://camunda-ci0:2375` to work on                                                   │Step 19 : CMD /usr/bin/supervisord
  a remote docker
feat(Makefile): add Makefile for build
chore(install-packages): allow apt-get output for debugging