Update Rails to 4.1.5

- [CVE-2014-3514](https://groups.google.com/d/msg/rubyonrails-security/M4chq5Sb540/CC1Fh0Y_NWwJ)

http://weblog.rubyonrails.org/2014/8/18/Rails_4_0_9_and_4_1_5_have_been_released/