Update main.yml

Author: danielapetito

.github/workflows/main.yml

@@ -50,7 +50,7 @@ jobs:
       env:
         HISTORY_DB_ADDRESS: "localhost"
       run: |
-        docker run -d -p 27017:27017 mongo
+        docker run -d -p 27017:27017 mongo:5.0.12
         ./tests/start-test.sh
         python3 -m pytest --cov-report=html --cov=history tests/
         coverage run -m pytest tests && coverage xml
@@ -138,4 +138,4 @@ jobs:
         publish_branch: gh-pages
         publish_dir: ./build-docs #fix when use .github/workflows/scripts/doc_aglio_api.sh
         keep_files: true
-        allow_empty_commit: false
+        allow_empty_commit: false