questions: make answer comparison smarter

use casefold() instead of lower() use strip() on the inbound answer in case someone had a trailing space

CodeChallenge/api/questions.py

@@ -105,7 +105,7 @@ def answer_next_question():
 
  data = request.get_json()
  text = data["text"]
- correct = str_cmp(text.lower(), q.answer.lower())
+ correct = str_cmp(text.casefold().strip(), q.answer.lower())
 
  ans = Answer.query.filter_by(user_id=user.id, question_id=q.id).first()