Rugged for GollumRails

Adding my rugged implementation. 

works:

- [ ] page
  - [x] page creation
  - [x] page update
  - [x] page delete
  - [x] page links
- [x] file
  - [x] file create
  - [x] file delete
- [x] gollum-lib
  - [ ] all internal methods
The use of `eval` is a serious security risk.<br>Redundant use of `Object#to_s` in interpolation.<br>`%`-literals should be delimited by `{` and `}`