Does not play nice with mockery

In my test code I'm registering a substitute module for `electron`.

When I enable `cache-require-paths` it will never use the substituted module, and instead error:

`Error: Cannot find module 'electron'`

``` js
require("cache-require-paths")

var mockery = require("mockery")
mockery.enable()
mockery.registerSubstitute("electron", "./electron_stub")

require("electron") // <-- bomb
```

This will work if I remove `cache-require-paths`.