remove accidentally committed backup dir for bs4

lib/bs5/__init__.py

lib/bs5/builder/__init__.py

lib/bs5/builder/_html5lib.py

lib/bs5/builder/_htmlparser.py

lib/bs5/builder/_lxml.py

lib/bs5/dammit.py

lib/bs5/diagnose.py

lib/bs5/element.py

lib/bs5/testing.py

lib/bs5/tests/__init__.py

lib/bs5/tests/test_builder_registry.py

lib/bs5/tests/test_docs.py

lib/bs5/tests/test_html5lib.py

lib/bs5/tests/test_htmlparser.py

lib/bs5/tests/test_lxml.py

lib/bs5/tests/test_soup.py

lib/bs5/tests/test_tree.py