add resource routes for categories, posts, comments, and votes
add shoulda matchers
Added basic CSS styling
migration for polymorphic associtaion
add polymirphic association to posts
fix polymorphic association
drop comments table
remove comment model
Merge pull request #2 from karinacarmona/refactor_models

Refactor models
adding controllers, routes and tests
finished adding user tests
halfway finished with users controller
organized more tests for categories
organized files together
adding rspec gem to gemfile
added gem, finished view test for categories
working on user views
adding more tests to users
finished adding most of user tests
adding sessions