Otherwise `helm plugin install …` will fail since
the install script fails to find the helm binary itself
during plugin installation.

Closes: #71

Closes: #70

Closes #69

Ansible needs this module to be installed on the control
machine for the k8s resource.

Closes #68

Pin packages in Dockerfile

Closes #59

See merge request openappstack/bootstrap!30

66 install apps

Closes #66

See merge request openappstack/bootstrap!32

improve behave

Closes #63

See merge request openappstack/bootstrap!29

Closes: #66

Two concurent docker jobs can't fetch the same cache, see
https://gitlab.com/gitlab-org/gitlab-runner/issues/1151