feat(pipeline): convert git flows

• convert existing git flows to gitlab pipeline tasks
• add test and build stage for application components

.gitlab-ci.yml

+stages:
+  - test
+  - build
+
+variables:
+  BASE_IMAGE_NAME: "$CI_REGISTRY_IMAGE/workadventure"
+
+.image_tag: &image_tag if [ "$CI_COMMIT_BRANCH" = "$CI_DEFAULT_BRANCH" ]; then image_tag=latest; elif [ -n "$CI_COMMIT_REF_SLUG" ]; then image_tag="$CI_COMMIT_REF_SLUG"; else image_tag="$CI_COMMIT_SHORT_SHA"; fi;
+.messages_setup: &messages_setup
+  - cd $CI_PROJECT_DIR/messages
+  - yarn install
+  - yarn run proto
+
+test_front:
+  stage: test
+  image: node:14.15.4-buster-slim
+  variables:
+    API_URL: "localhost:8080"
+  before_script:
+    - *messages_setup
+    - yarn run copy-to-front
+    - cd $CI_PROJECT_DIR/front
+    - yarn install
+    - ./templater.sh
+    - yarn run build
+  script:
+    - yarn run lint
+    - yarn test
+  needs: [ ]
+
+test_pusher:
+  stage: test
+  image: node:14.15.4-buster-slim
+  before_script:
+    - *messages_setup
+    - yarn run copy-to-pusher
+    - cd $CI_PROJECT_DIR/pusher
+    - yarn install
+    - yarn run tsc
+  script:
+    - yarn run lint
+    - yarn test
+  needs: [ ]
+
+test_back:
+  stage: test
+  image: node:14.15.4-buster-slim
+  before_script:
+    - *messages_setup
+    - yarn run copy-to-back
+    - cd $CI_PROJECT_DIR/back
+    - yarn install
+    - yarn run tsc
+  script:
+    - yarn run lint
+    - yarn test
+  needs: [ ]
+
+build_front_image:
+  stage: build
+  image:
+    name: gcr.io/kaniko-project/executor:debug
+    entrypoint: [ "" ]
+  script:
+    - *image_tag
+    - mkdir -p /kaniko/.docker
+    - echo "{\"auths\":{\"$CI_REGISTRY\":{\"username\":\"$CI_REGISTRY_USER\",\"password\":\"$CI_REGISTRY_PASSWORD\"}}}" > /kaniko/.docker/config.json
+    - /kaniko/executor --context $CI_PROJECT_DIR --dockerfile $CI_PROJECT_DIR/front/Dockerfile --destination $BASE_IMAGE_NAME-front:$image_tag
+  needs: [ ]
+
+build_back_image:
+  stage: build
+  image:
+    name: gcr.io/kaniko-project/executor:debug
+    entrypoint: [ "" ]
+  script:
+    - *image_tag
+    - mkdir -p /kaniko/.docker
+    - echo "{\"auths\":{\"$CI_REGISTRY\":{\"username\":\"$CI_REGISTRY_USER\",\"password\":\"$CI_REGISTRY_PASSWORD\"}}}" > /kaniko/.docker/config.json
+    - /kaniko/executor --context $CI_PROJECT_DIR --dockerfile $CI_PROJECT_DIR/back/Dockerfile --destination $BASE_IMAGE_NAME-back:$image_tag
+  needs: [ ]
+
+build_pusher_image:
+  stage: build
+  image:
+    name: gcr.io/kaniko-project/executor:debug
+    entrypoint: [ "" ]
+  script:
+    - *image_tag
+    - mkdir -p /kaniko/.docker
+    - echo "{\"auths\":{\"$CI_REGISTRY\":{\"username\":\"$CI_REGISTRY_USER\",\"password\":\"$CI_REGISTRY_PASSWORD\"}}}" > /kaniko/.docker/config.json
+    - /kaniko/executor --context $CI_PROJECT_DIR --dockerfile $CI_PROJECT_DIR/pusher/Dockerfile --destination $BASE_IMAGE_NAME-pusher:$image_tag
+  needs: [ ]
+
+build_uploader_image:
+  stage: build
+  image:
+    name: gcr.io/kaniko-project/executor:debug
+    entrypoint: [ "" ]
+  script:
+    - *image_tag
+    - mkdir -p /kaniko/.docker
+    - echo "{\"auths\":{\"$CI_REGISTRY\":{\"username\":\"$CI_REGISTRY_USER\",\"password\":\"$CI_REGISTRY_PASSWORD\"}}}" > /kaniko/.docker/config.json
+    - /kaniko/executor --context $CI_PROJECT_DIR --dockerfile $CI_PROJECT_DIR/uploader/Dockerfile --destination $BASE_IMAGE_NAME-uploader:$image_tag
+  needs: [ ]
+
+build_maps_image:
+  stage: build
+  image:
+    name: gcr.io/kaniko-project/executor:debug
+    entrypoint: [ "" ]
+  script:
+    - *image_tag
+    - mkdir -p /kaniko/.docker
+    - echo "{\"auths\":{\"$CI_REGISTRY\":{\"username\":\"$CI_REGISTRY_USER\",\"password\":\"$CI_REGISTRY_PASSWORD\"}}}" > /kaniko/.docker/config.json
+    - /kaniko/executor --context $CI_PROJECT_DIR --dockerfile $CI_PROJECT_DIR/maps/Dockerfile --destination $BASE_IMAGE_NAME-maps:$image_tag
+  needs: [ ]