Added unit tests and models Item, Category and Lot
Added association tests
Regexp checking with test for Item is added
Added comments for regexp
Some more tests and validations for Lot
Regexp have been replaced with naitve methods
Devise has been installed
Self one-to-many association have been set for categories
Item tests have been refactored
Category tests have been refactored
Controllers and views for Category with bootstrap
Admin namespace added and applied for categories