Create with pre-defined primary key should not POST with /models/:id

When creating a record with a pre-defined id (primary key) value,
the POST resource generated from Her was sent with an `:id` resource.

It should not have the `id` portion on the path.

``` ruby
Model.create(id: '1234')
```

resulted in an incorrect request path being sent to the service

```
POST /models/1234
```

It should be just the resource path with data in the body.

```
POST /models
```
