Update pyroma from 2.3.1 to 2.4

Author: pyup-bot

dev-requirements.txt

@@ -14,7 +14,7 @@ pip_check_reqs==2.0.3
 pydocstyle==2.1.1  # Lint docstrings
 pyenchant==2.0.0  # Bindings for a spellchecking sytem
 pylint==2.1.1  # Lint
-pyroma==2.3.1  # Packaging best practices checker
+pyroma==2.4  # Packaging best practices checker
 pytest-cov==2.5.1  # Measure code coverage
 pytest-envfiles==0.1.0  # Use files for environment variables for tests
 pytest==3.7.1  # Test runners