Added sidebar navigation

Features included in this request:
* Added sidebar
* Sidebar affix behaviour with custom js
* Sidebar collapse behaviour using Bootstrap
* Project documents visible from show/index page
* Flash messages disappear after 5 seconds
* Added ```seeds.rb``` file

Features **NOT** included in this request:
* Documents controller index page still exists, will create a chore to remove that
* Jasmine testing for sidebar behaviour is not yet ready for production