feat: Helper script for clearing out test database for postgres (#863)

tests/clear_postgres_db.py

@@ -0,0 +1,8 @@
+from sqlalchemy import create_engine, MetaData
+
+engine = create_engine("postgresql+pg8000://memgpt:memgpt@localhost:8888/memgpt")
+
+meta = MetaData()
+meta.reflect(bind=engine)
+
+meta.drop_all(bind=engine)