Update handlebars to v1.3.0

```
$ rake test
Run options: 

# Running tests:

Finished tests in 1.980119s, 7.5753 tests/s, 11.1104 assertions/s.                                      
15 tests, 22 assertions, 0 failures, 0 errors, 0 skips

ruby -v: ruby 2.0.0p247 (2013-06-27 revision 41674) [x86_64-darwin12.4.0
```