Merge pull request #540 from flori/remove-ruby-1-8

Removed code for Ruby 1.8

Author: hsbt

tests/json_encoding_test.rb

@@ -86,9 +86,7 @@ def test_unicode
   def test_chars
     (0..0x7f).each do |i|
       json = '["\u%04x"]' % i
-      if RUBY_VERSION >= "1.9."
-        i = i.chr
-      end
+      i = i.chr
       assert_equal i, parse(json).first[0]
       if i == ?\b
         generated = generate(["" << i])