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
Useless assignment to variable - `encoding`.<br>Prefer double-quoted strings unless you need single quotes to avoid extra backslashes for escaping.