Update file.rb

added copy_to method to RubyBox::File
RubyBox::File.copy_to( FolderID, name<optional> )
added some tests around copying a file. changed copy_to, to take either a folder or a folder.id.
Updating README.markdown with the #copy_to method on RubyBox::File.
upping version #.
fixed typo.
fixed typo in readme.
Merge pull request #46 from attachmentsme/copy-method

added #copy_to method to File