input: Write a python function to fetch all records from the 'people' table and return them as a list of tuples.
  assert fetch_all_records() == [('John', 25, 'Male'), ('Mary', 30, 'Female'), ('Jane', 18, 'Female')]
output: def fetch_all_records():
      import sqlite3
      conn = sqlite3.connect('example.db')
      cursor = conn.cursor()
      cursor.execute("SELECT * FROM people")
      records = cursor.fetchall()
      conn.close()
      return records