Because the service is not available in GitLab CE :(

Unifies and secures the images a bit more

Useful for downloading or calling triggers through these images, just as
useful as wget.

Also remove duplicate attempted installation of wget

Also disable SSL cert check as it won't match

- Auto pushes image to Docker Hub
- Automatically triggers cmake-qt5-qommando build too

Tag is renamed to the full username/repo name scheme, to make it equal
to Docker Hub's full name.