Github to gitlab migration for gitlab ci integration

[rhanka]

We should migrate to Gitlab, to take benefit from gitlab-ci integration.

Dockerfile & docker-compose have been proved to been really easy for npm & vue, and gitlab-ci is just a yaml wrapping Dockerfile.

A first draft of .gitlab-ci.yml has been pushed to the project).

[Tristramg]

I really like gitlab for tons of reasons, and gitlab-ci is amazing, but for this project a good old https://travis-ci.org/ can also do the work.

I’ll make a merge request