Run project as docker container

# By kingcody
# Via Kamil Trzciński (1) and kingcody (1)
* 'master' of github.com:ayufan/gitlab-ci-multi-runner:
  Remove WorkingDirectory

Remove WorkingDirectory from Systemd service

# By Cody Mize
# Via Cody Mize (1) and Kamil Trzciński (1)
* 'master' of github.com:ayufan/gitlab-ci-multi-runner:
  MongoDB image name is `mongo`

By default systemd will use the respective user's home directory if run as user
see: http://man7.org/linux/man-pages/man5/systemd.exec.5.html#OPTIONS

MongoDB image name is `mongo`