Try with no build cache

Trying to figure out why build is failing with this error:

https://ci.appveyor.com/project/GaryEwanPark/gep13-github-io/build/1.0.67

```Liquid Exception: undefined method `match' for nil:NilClass in _posts/2014-09-05-setup-appveyor-to-deploy-octopress-site-to-github-pages.md```