Publish optional package on npmjs.

[mightymax]

The optional dependency on xpath-iterator is referring to a git URL. While this is perfectly fine in most cases, in some environments this will fail. Even though it is an optional dependency, yarn will still download it (not sure about npm). Some users have strict policies for security reasons on where they can download dependencies from. Some might even have a mirror from npmjs.com and checks/limits that mirror.

Can you please publish the xpath-iterator package on npmjs.com and change the options dependency to reflect this?

Thanks!