Fix use of Flask's redirect() in source code

Currently, code seems to result in "405 Method Not Allowed" HTTP Response (on Chrome), when one submits the 'How many eyes do you have?' question. I see two ways to fix this.
    
First, call redirect('/usefulfunction_lulu', code=307) instead of redirect('/usefulfunction_lulu'). See more about the underlying issue here: http://stackoverflow.com/questions/15473626/make-a-post-request-while-redirecting-in-flask
    
Second, omit the "methods=['POST']" in @app_lulu.route('/usefulfunction_lulu'). I suggest this, because it is consistent with 7_finale.rst, in which @app_lulu.route('/main_lulu') also does not restrict on POST.