[fix] Swaping out svg logo for the correct version

Sorry this took so long and thanks to everyone who pointed it out!
Hopefully this fixes things. The 'o' in openfarm still looks a bit too small and off to me, but this is a lot better for now! (Also if a browser doesn't support svgs it'll fall back on the *huge* (but only 30kb) png.)

![yes](https://cloud.githubusercontent.com/assets/220240/3451977/4b58a672-01a7-11e4-91a7-b6480b8e79eb.gif)