:yum: Added Invoices views
:two_hearts: Added Invoices and line items migration and models
:boom: Added Gemfile and javascripts for invoices members and contacts
:+1: Added js
:notes: Added a link to generate certificate
:alien: Added Invoice controller
::open_hands:: Added before_filter to force login
:cop: Commit lib folder
:skull: Fixed Certificate generation
:love_letter: Fixed emails js
:feelsgood: Fixed locales
:finnadie: Switch category to tags
:boar: Added Invoices to navbar
:frog: Fixed HTML