#2 change to work with install_options nodepath in puppet3

This is in response to:

https://github.com/rlister/puppet-npm-simple/issues/2

I ran into this issue when upgrading from puppet 2.7.21 to puppet 3.2.4, I noticed the change wasn't made, after making the following changes it now works for me.  

Keep in mind I was not seeing the errors when running puppet agent -t on nodes, instead, the error was only showing up under failures in puppet-dashboard.