FIX: typo in pylint makefile command.

Makefile

@@ -23,7 +23,7 @@ black:
 	black rocketpy/ tests/ docs/
 
 pylint:
-	-pylint rocketpy tests --output=.pylint-report.txt
+	pylint rocketpy tests --output=.pylint-report.txt
 
 build-docs:
 	cd docs && python3 -m pip install -r requirements.txt && make html