Migrate to http://blog.roberteshleman.com

* Change URL slug from `blog/` to `/` in `_config.yml`
* Update domain and email in `_config.yml`
* Add `jekyll-redirect-from` Gem
* Add `redirect_from` path to each blog post to redirect from `blog/`
* Update pagination path to format `page/2/`
* Move archives to `archives/` path from `blog/archives/`
* Update links to archives in layouts