input: Write a python function to generate a SHA-1 hash token using username, auth_key, business_name, and the current date.
  assert generate_token('user1', 'my_auth_key', 'business1', '2023-10-01') == '0e2f4ad5a6f8c9f026a12f287d1c8d5a1f7d5e52'
  assert generate_token('admin', 'auth_key', 'projectX', '2023-10-10') == 'd2a98f3a5bd6b8cb0a15f1a280d2cf8a6e2f6e5c'
output: import hashlib
  
  def generate_token(username, auth_key, business_name, current_date):
      data = f"{username}{auth_key}{business_name}{current_date}"
      sha1_hash = hashlib.sha1(data.encode()).hexdigest()
      return sha1_hash