fixes for categories controller specs
fixes for product model specs
fixed specs for review model and category model
added displaying review's author
fixed user registration

added permitted params
changed db config

changed test db name and pass
added assign user to review
updated product model and controller

added admin stub to products controller spec and user_id in product
model spec
Revert "fixes for product model specs"

This reverts commit 2d932f33fa012ff718ff91620b033116aa697fda.
products model meet specs