Specifying rootDir with linked module breaks css-modulesify #84

In a project, I have some components stored in separate modules, and the main module installs those modules in using npm link (i.e., creating symlinks to them from node_modules). The structure looks like this:

project
  main
    package.json
    node_modules
      componentA -> ../../componentA
      componentB -> ../../componentB
  componentA
    package.json
  componentB
    package.json

main, componentA and componentB all use CSS Modules. I'm running browserify from of the main module, and have css-modulesify configured with global: true

I ran into problems with css-modulesify constructing paths to filenames in componentA and componentB incorrectly. I ultimately traced this down to the rootDir option. Originally, I had rootDir set to /path/to/project/main, since I thought rootDir only controlled formatting of generated classnames. Setting rootDir to /path/to/project fixed the issues.

Is it the intended behavior for rootDir to cause css-modulesify to fail if there are any css files that are relatively 'higher' that rootDir? If it is, I think it would probably be good to change the documentation in the README to be something like:

• rootDir: absolute path to your project's root directory. This is optional but providing it will result in better generated classnames. If provided, attempting to bundle any css files accessed via a parent of rootDir will fail