Travis: fetch Git tags before running code scans

This allows builds to start faster but still has the full
history available for code analysis

.travis.yml

@@ -39,6 +39,7 @@ script:
     - git diff --name-only $TRAVIS_COMMIT_RANGE | xargs pre-commit run --files
     - pipenv run safety check
 after_success:
+    - git fetch --unshallow --tags
     - pipenv run coverage xml
     - sonar-scanner
     - coveralls