Serve current commit price with no caching

As complained about here:
http://www.reddit.com/r/Bitcoin/comments/1yu6l7/someone_just_sent_5000_in_btc_to_open/cfnsp03

The need to explicitly forbid caching is explained here:
https://github.com/github/markup/issues/224

FREEBIE
Merge pull request #33 from backspace/break-current-commit-price-cache

Serve current commit price with no caching