properly define the public api

lib/gollum/file.rb

@@ -1,23 +1,25 @@
 module Gollum
   class File
-    attr_accessor :wiki, :blob, :version
-
     # Initialize a file.
     #
     # wiki - The Gollum::Wiki in question.
     #
     # Returns a newly initialized Gollum::File.
     def initialize(wiki)
-      self.wiki = wiki
+      @wiki = wiki
+      @blob = nil
     end
 
     # The raw contents of the page.
     #
     # Returns the String data.
     def raw_data
-      self.blob.data rescue nil
+      @blob.data rescue nil
     end
 
+    # The Grit::Commit version of the file.
+    attr_reader :version
+
     #########################################################################
     #
     # Private
@@ -31,10 +33,10 @@ module Gollum
     #
     # Returns a Gollum::File or nil if the file could not be found.
     def find(name, version)
-      commit = self.wiki.repo.commit(version)
+      commit = @wiki.repo.commit(version)
       if blob = commit.tree / name
-        self.blob = blob
-        self.version = commit
+        @blob = blob
+        @version = commit
         self
       else
         nil