Enumerator.new is deprecated in ruby 2.0
test against ruby 2.0 on travis ci
Convert invalid strings from binary to utf-8

Since changing the encoding from UTF8 to UTF8 doesn't do anything (see
http://bugs.ruby-lang.org/issues/7967#note-1), change the source encoding
to binary (ie. ascii-8bit) and replace all undefined characters.
Merge pull request #64 from coffeejunk/ruby2

updates for ruby 2.0