input: Write a python function to identify and remove spam comments from a list of comments.
  assert remove_spam_comments(['Get a free discount!', 'Hello there', 'Discount on all items!']) == ['Hello there']
  assert remove_spam_comments(['Join us for free!', 'This is a genuine comment', 'Huge discount available']) == ['This is a genuine comment']
  assert remove_spam_comments(['Hello world', 'No spam here', 'Just a normal comment']) == ['Hello world', 'No spam here', 'Just a normal comment']
output: def remove_spam_comments(comments):
      spam_keywords = ["free", "discount", "join", "huge"]
      def is_spam(comment):
          return any(keyword in comment.lower() for keyword in spam_keywords)
      return [comment for comment in comments if not is_spam(comment)]