refactored current_user helper
added link to sign up in navbar
Wrote failing and pending tests for comments

  *created a comment factory
post show page displays all comments
wrote failing feature test for creating a comment
added a form for a new comment
tweaked form helper for new comment
added nested resources for comments
debugged feature test
changed form_for helper for nested resources
made comments attr_accessible and added one validation
controller tests for comments#create
implmented comments#create
wrote failing feature test for editing a post
added link to edit comment in post show page
added routes for editing comments
wrote failing controller test for comments#edit
created a view for comments#edit
wrote failing test for comments#edit
implemented comments#edit