Add a check for vulnerabilities in dependencies in gitlab-ci

.gitlab-ci.yml

@@ -2,6 +2,7 @@ stages:
   - build
   - test
 
+
 build-ubuntu:
   stage: build
   image: poezio/build-base:latest
@@ -13,6 +14,13 @@ build-ubuntu:
     paths:
       - dist/
 
+security-check:
+  stage: test
+  image: python:3
+  script:
+    - pip3 install safety
+    - safety check -r requirements.txt
+
 test-ubuntu:
   stage: test
   image: poezio/test-base:latest