Ruby 1.9 Hash syntax is still not parsed correctly

``` ruby
Hash[*CodeRay.scan("{:foo => 'bar', foo: 'bar'}", :ruby).tokens]
```

``` ruby
 {"{"=>:operator,
 ":foo"=>:symbol,
 " "=>:space,
 "="=>:operator,
 ">"=>:operator,
 :begin_group=>:string,
 "'"=>:delimiter,
 "bar"=>:content,
 :end_group=>:string,
 ","=>:operator,
 "foo"=>:key,        # this should be parsed as `:symbol`
 ":"=>:operator,     # and this too
 "}"=>:operator}
```
