Add new file

backend/secfit/.gitlab-ci.yml

+deploy:
+  stage: deploy
+  image: python:3.8.5-slim
+
+  before_script:
+    - apt-get clean
+    - pip install -r backend/secfit/requirements.txt
+
+  cache:
+    paths:
+      - ~/.cache/pip/
+
+  services:
+    - postgres:latest
+
+  script:
+    - apt-get update -qy --allow-insecure-repositories
+    - apt-get install -y ruby-dev
+    - apt-get install git -yqq
+    - apt-get install curl -y
+    - gem install dpl
+    - dpl --provider=heroku --app=secfit-group15 --api-key=$HEROKU_API_KEY --skip_cleanup
+  only:
+    refs:
+      - master