Remove calls to Vagrant::Environment#load! to make compatible with 1.1.0.dev

Based on this issue from over two years ago, Vagrant::Environment no
longer has a #load! method and lazy-loads its resources. I've removed
calls to #load! and it seems to fix the problem.

There's a good chance I'm not understanding the problem since I'm relatively new to the Chef ecosystem. Feel free to advise :)

https://github.com/mitchellh/vagrant/issues/236