Update .gitlab-ci.yml

For each commit in develop branch:
+ Add tests
+ Add docker build image

.gitlab-ci.yml

@@ -14,9 +14,10 @@ testing:
   extends: .python_job
   stage: test
   rules:
-  - if: '$CI_COMMIT_BRANCH == "stable"'
-  - if: '$CI_MERGE_REQUEST_TARGET_BRANCH_NAME == "stable"'
-  - if: '$CI_MERGE_REQUEST_TARGET_BRANCH_NAME == "develop"'
+    - if: '$CI_COMMIT_BRANCH == "stable"'
+    - if: '$CI_COMMIT_BRANCH == "develop"'
+    - if: '$CI_MERGE_REQUEST_TARGET_BRANCH_NAME == "stable"'
+    - if: '$CI_MERGE_REQUEST_TARGET_BRANCH_NAME == "develop"'
   script:
     - cd tests
     - poetry run pytest --junitxml=report.xml
@@ -29,14 +30,29 @@ formatters:
   extends: .python_job
   stage: test
   rules:
-  - if: '$CI_COMMIT_BRANCH == "stable"'
-  - if: '$CI_MERGE_REQUEST_TARGET_BRANCH_NAME == "stable"'
-  - if: '$CI_MERGE_REQUEST_TARGET_BRANCH_NAME == "develop"'
+    - if: '$CI_COMMIT_BRANCH == "stable"'
+    - if: '$CI_COMMIT_BRANCH == "develop"'
+    - if: '$CI_MERGE_REQUEST_TARGET_BRANCH_NAME == "stable"'
+    - if: '$CI_MERGE_REQUEST_TARGET_BRANCH_NAME == "develop"'
   script:
     - poetry run isort --check --diff mbtrack2/
     - poetry run yapf -d -r mbtrack2/
 
-docker:
+docker_develop:
+  stage: build_docker
+  rules:
+    - if: '$CI_COMMIT_BRANCH == "develop"'
+  image: docker:latest
+  services:
+    - docker:dind
+  variables:
+    CONTAINER_RELEASE_IMAGE: ${CI_REGISTRY_IMAGE}:develop
+  script:
+    - echo "${CI_REGISTRY_PASSWORD}" | docker login -u ${CI_REGISTRY_USER} --password-stdin ${CI_REGISTRY}
+    - docker build --pull -t ${CONTAINER_RELEASE_IMAGE} .
+    - docker push ${CONTAINER_RELEASE_IMAGE}
+
+docker_stable:
   stage: build_docker
   rules:
     - if: '$CI_COMMIT_TAG'
@@ -53,7 +69,7 @@ docker:
     - docker push ${CONTAINER_RELEASE_IMAGE}
     - docker push ${CONTAINER_TAG_IMAGE}
 
-pip:
+pip_stable:
   extends: .python_job
   stage: build_pip
   rules: