Fix another N+1 on home.

* Previously, had a method User#pick_for(game) which called one query per game.
* Now, just select current_user.picks and we can test if the game is in the collection.
Oops: first doesn't take a block - use find to solve the N+1
N+1's everywhere. current_user.picks must include game.
Make heroku happy - disable initialize_on_precompile
Add rake task to scrape scores from ESPN Bottomline