Merge pull request #14 from lizrush/sessions

Sessions
created product validations
added product model validations specs, and association spec
added links on index for easy use and fixed star rating to 1 thru 5
changes recommended from bookis
add validation notes to models
Merge pull request #16 from lizrush/validations-with-specs

Validations with specs
chages to products for validations
Merge branch 'master' of github.com:lizrush/congo
chages to products for validations
adds review specs and tests product name uniqueness
added categories
fixed weird migration thing(ihope)
adds category controller actions and resource in config
adds views for categories
Adds stock and image migration for products
adds carrierwave to products
Working photo uplaods. YAY
merge master into categories
removed merge lines in db schema