Raffler link on website

# Why
Because I heard some people complaining that it was hard to remember the raffler url, I've added a link to the raffler for the upcoming meetup. This might help people find the raffler and make it easier for them to check-in.

# What it looks like
![screen shot 2014-09-22 at 23 18 44](https://cloud.githubusercontent.com/assets/106844/4364246/30cf9864-429e-11e4-80f3-4843563857ab.png)

It might need work on the location, looks and copy, so shoot!