removed accessor method and fixed tests

lib/jekyll/convertible.rb

@@ -3,6 +3,10 @@
 #
 # Requires
 #   self.site -> Jekyll::Site
+#   self.content=
+#   self.data=
+#   self.ext=
+#   self.output=
 module Jekyll
   module Convertible
     # Return the contents as a string

lib/jekyll/post.rb

@@ -18,12 +18,9 @@ module Jekyll
       name =~ MATCHER
     end
 
-    attr_accessor :site, :date, :slug, :ext, :published, :data, :content, :output, :tags
+    attr_accessor :site
-    attr_writer :categories
+    attr_accessor :data, :content, :output, :ext
-
+    attr_accessor :date, :slug, :published, :tags, :categories
-    def categories
-      @categories ||= []
-    end
 
     # Initialize this Post instance.
     #   +site+ is the Site

test/test_post.rb

@@ -36,6 +36,7 @@ class TestPost < Test::Unit::TestCase
       end
 
       should "keep date, title, and markup type" do
+        @post.categories = []
         @post.process(@fake_file)
 
         assert_equal Time.parse("2008-10-19"), @post.date