Fixed - password not set for newly created user

Tastypie changed how bundle.obj gets assigned a new instance of model class sometime during 0.9.15 to 0.10.0. Better keep an eye on changelogs. Following line was a culprit -
https://github.com/toastdriven/django-tastypie/blob/v0.10.0/tastypie/resources.py#L2078
Signed-off-by: Pankaj Singh <psjinx@gmail.com>