Add integration tests, reorg tests

sbws/util/stem.py

tests/integration/__touch__.py

tests/integration/conftest.py

tests/integration/test_stem.py

tests/testnets/reproducible.tar

tests/unit/__init__.py

tests/unit/conftest.py

tests/unit/core/test_cleanup.py

tests/unit/core/test_generate.py

tests/unit/core/test_stats.py

tests/unit/globals.py

tests/unit/lib/test_results.py

tests/unit/lib/test_v3bwfile.py

tests/unit/util/test_config.py

tests/unit/util/test_userquery.py

tox.ini