Add support for model bindings in route params

[benkingcode]

I noticed when I set my url.namespace to api/v1/{tenant}, if the tenant param was bound to a model the generated URLs would contain the JSON serialization, like so;

"links": {
    "self": "http:\/\/api.example.test\/api\/v1\/{\"id\":1,\"name\":\"Tenant Name\",\"created_at\":\"2020-04-20T13:57:55.000000Z\",\"updated_at\":\"2020-04-20T13:57:55.000000Z\",\"slug\":\"test-slug\"}\/products\/1"
}

With this fix, bound models correctly use the route key;

"links": {
    "self": "http:\/\/api.example.test\/api\/v1\/test-slug\/products\/1"
}

[lindyhopchris]

Thanks for highlighting this - it definitely needs fixing and great to see you've added a test too!

Just one change which is I have a preference for checking for interfaces where they exist.

I'm not sure why the tests are failing so I'll investigate that seperately as I believe it is unrelated to the changes you've made.

[benkingcode]

Cool, made your suggested change! The tests all passed locally for me so not sure why Travis is showing a failure.

[lindyhopchris]

Thanks! Looks like a temporary failure - knowing Laravel they probably had something breaking in their releases which they've then fixed.