Added missing file. fixes #114

Author: hsbt

Manifest.txt

@@ -64,6 +64,7 @@ lib/rake/default_loader.rb
 lib/rake/dsl_definition.rb
 lib/rake/early_time.rb
 lib/rake/ext/core.rb
+lib/rake/ext/fixnum.rb
 lib/rake/ext/pathname.rb
 lib/rake/ext/string.rb
 lib/rake/file_creation_task.rb