Use travis (bug 1066167)

Fixes [bug 1066167](https://bugzilla.mozilla.org/show_bug.cgi?id=1066167)
It's supposed to raise an error in spidermonkey, and this test makes sure it doesn't break the validator.

`12a4` is invalid, the same way `09999999` is an invalid octal (a number with the `0` prefix is supposed to be an octal... but it seems it's not anymore in later versions of spidermonkey).