Merge pull request #33 from JessicaG/header

Header
Merge branch 'master' into update_UAU_tests
Merge pull request #39 from JessicaG/update_UAU_tests

all UAU tests passing with vendor test additions
changed header dropdown to browse by vendors, categories (added controller and view), and items
Merge branch 'master' into header
categories index page styled
removed links from categories index
UAU tests green