input: Write a function to create a Celery task in Python to send an email. The function should accept recipient's name, email, subject, and message as inputs and return nothing. Ensure the task is correctly defined and utilizes Flask-Mail to send the email.
  assert send_email('John Smith', 'john@example.com', 'Hello World', 'This is a test email.')==None
  assert send_email('Jane Doe', 'jane@example.com', 'Greetings', 'This is another test email.')==None
output: def send_email(name, email, subject, message):
      from flask_mail import Message
      from your_app import mail
      msg = Message(subject, sender='your_email@example.com', recipients=[email])
      msg.body = f"Dear {name},\n\n{message}"
      mail.send(msg)