Integer Resource slugs result in Transifex error

[nyergler]

When using txlib.api.resources.Resource to create a new Resource, the slug must be specified as a string. We're pulling data from another system that uses integer identifiers, and if we don't case that to a string we get the following back from the API:

txlib.http.exceptions.RequestError: Piston/0.2.3rc1 (Django 1.3.1) crash report:

Method signature does not match.

Resource does not expect any parameters.

I'm not sure if the answer is to handle this in txlib, or to fix the server-side code to cast input to strings.

[mpessas]

Well, the API says that strings should be used for the slug field, so this should be fixed probably here.
But we will have to improve the error message, as well.