input: Write a Python function to list all students from the StudentDatabase.
  assert len(list_students('test_students.db')) == 0
  assert 'John Doe' in [student[1] for student in list_students('test_students.db')]
  assert 'Adam Smith' not in [student[1] for student in list_students('test_students.db')]
output: def list_students(db_path):
      import sqlite3
  
      conn = sqlite3.connect(db_path)
      cursor = conn.cursor()
  
      cursor.execute("SELECT * FROM students")
      students = cursor.fetchall()
  
      conn.close()
      return students