Merge branch 'gitlab_relative_include' into 'master'

Use project based include rather than hardcoded path for CI

See merge request !86

.gitlab-ci.yml

-include: 'https://gitlab.idiap.ch/bob/bob.devtools/raw/master/bob/devtools/data/gitlab-ci/single-package.yaml'
+include:
+  - project: 'bob/bob.devtools'
+    ref: master
+    file: '/bob/devtools/data/gitlab-ci/single-package.yaml'