Add raise_on_blank_find_param resource setting

[stokarenko]

The problem comes from #329

That is a bit curios, but json_api_client returns an array from .find method, always.
The history of this fact was discussed here

So, when we searching for a single resource by primary key, we typically write the things like

admin = User.find(id).first

The next thing which we need to notice - json_api_client will just interpolate the incoming .find param to the end of API URL, just like that:

http://somehost/api/v1/users/{id}

What will happen if we pass the blank id (nil or empty string) to the .find method then?.. Yeah, json_api_client will try to call the INDEX API endpoint instead of SHOW one:

http://somehost/api/v1/users/

Lets sum all together - in case if id comes blank (from CGI for instance), we can silently receive the admin variable equal to some existing resource, with all the consequences.

Even worse, admin variable can equal to random resource, depends on ordering applied by INDEX endpoint.

If you prefer to get JsonApiClient::Errors::NotFound raised, please define in your base Resource class:

class Resource < JsonApiClient::Resource
  self.raise_on_blank_find_param = true
end

[gaorlov]

This looks good! Thanks for taking the time!

[gaorlov]

Excellent! As soon as tests pass, I'll release this as 1.11.0.
Thanks again for taking the time!

[gaorlov]

Oh. one last thing: can you please add a brief description to CHANGELOG.md? Thanks!

[stokarenko]

on my way! )

[stokarenko]

@gaorlov done )