add home link jumbotron on new comment page
remove votes column from links
add user table
add user model
set up basic users controller
add user password confirmation accessors
validate user passwords
add integration testing for link creation
add integration test for link creation errors
create user login
add functionality for logged in user to comment
add validation for user having a single vote per link
add further validation for user votes
set up vote controller
add link sorting algorithm based on time and votes