updated for Rails 3/4

I pulled down the sample app for Seer and did a quick and dirty update to get it working under Rails 3/4. I am running Rails 4, but I don't think there's anything that won't work with 3.2. The only error I can see is the images/background.png is not being found by the web server. But all of the charts work. I had to set most ":colors => []" to get color working in the charts. The geo-map chart comes up but does not show any data on the map. This would let people using modern versions of Rails check out the gem. Don't know if you would want to archive the old version for anyone running Rails 2, but if they are building a new app they should probably be on v4. BTW this is a great gem!