no longer do we need to define [:attrs] if our url.
only URLify the url IF the user has specified a primary key using the `:key` syntax in the url.

This is common in the show and delete urls, where the user might want to define:

```
showURL = 'http://api.com/tshirt/:_id';
deleteURL = 'http://api.com/tshirt/:_id';
```

In both these cases the GET and DELETE urls will recognize the user wants to pass the `_id` attr of the model in the url, instead of a query param.
update tests to no longer expect slash `/` in the url.
update tests to expect config data with http requests.
update tests to not expect urls with `[:attrs]`
update readme
Merge branch 'master' of https://github.com/FacultyCreative/ngActiveResource into features/use-config.params
Merge branch 'master' into features/use-config.params
Fix querystrings
Merge pull request #11 from FacultyCreative/features/use-config.params

Features/use config.params