Revert "Fix invalid CI image"

default:

  image: alpine

stages:

 - build

 - push

docker_build:

  stage: build

  before_script:

  - apk add bash

  script: BUILD_EXTRA="--no-cache --pull" ./build.sh $CI_REGISTRY_IMAGE

docker_push:

  stage: push

  before_script:

  - apk add docker

    - docker login -u gitlab-ci-token -p $CI_JOB_TOKEN $CI_REGISTRY

  script:

    - docker push ${CI_REGISTRY_IMAGE}:oldstable