Added check to make sure user is signed in before creating/destorying post and passed current user to new post form
Added signed_in_user function to check whether user is signed in and redirect them to sign in page if not
Form now passes in user id automatically as hidden form attribute
Added button for user to create new post
Merge branch '6_user_must_be_logged_in_to_post'

Conflicts:
	app/views/users/show.html.erb