Major improvments

- Refactored method names
  - `where_params_eq` is now `with_params`
	- `route_params` is now `grape_documentation`
- Support for group, order, join
- Replaced grape grape-0.4.x with grape-0.5.x
- Coveralls works, I think?
- Corrected docs
Merge pull request #4 from Adaptly/pc-add-joins

Major improvments