Using Karma available at a network drive

### Expected behavior

Using Karma available in a network drive should run as an local machine.
### Actual behavior

Karma can't find karma plugin files. If instead of network drive UNC pathname I use a mapped network drive, then it works.

Doesn't work:
`////node_modules/.bin/karma.cmd start karma.conf.js --log-level-debug`
Works:
`Y://node_modules/.bin/karma.cmd start karma.conf.js --log-level-debug`
### Enviroment Details
- Karma version (output of `karma --version`): v.0.13.22
### Steps to reproduce the behaviour

Hi there,

I want to use Karma in my project, with Karma being in a network drive. My local machine is Windows, and the network drive also is.

I've generated the node_modules folder in the project via 'npm install' and moved them to the network drive. In my local project they work without problems.

Next I run the following, pointing to Karma in the network drive:

`////node_modules/.bin/karma.cmd start karma.conf.js --log-level-debug`

The problem is that Karma third party node modules are not being located correctly:

```
12 05 2016 10:06:51.765:DEBUG [plugin]: Loading karma-* from \\\\\node_modules
12 05 2016 10:06:51.765:DEBUG [plugin]: Loading plugin \\\\node_modules/karma-chrome-launcher.
12 05 2016 10:06:52.058:DEBUG [plugin]: Loading plugin \\\\node_modules/karma-coverage.
12 05 2016 10:06:57.514:DEBUG [plugin]: Loading plugin \\\\node_modules/karma-jasmine.
12 05 2016 10:06:57.575:DEBUG [plugin]: Loading plugin \\\\node_modules/karma-jasmine-html-reporter.
12 05 2016 10:06:57.626:DEBUG [plugin]: Loading plugin \\\\node_modules/karma-phantomjs-launcher.
12 05 2016 10:06:58.011:DEBUG [plugin]: Loading plugin \\\\node_modules/karma-requirejs.
12 05 2016 10:06:58.485:WARN [watcher]: Pattern "\\\\node_modules\requirejs\bin/../require.js" does not match any file.
12 05 2016 10:06:58.489:WARN [watcher]: Pattern "\\\\node_modules\karma-requirejs\lib\adapter.js" does not match any file.
12 05 2016 10:06:58.489:WARN [watcher]: Pattern "\\\\node_modules\jasmine-core\lib/jasmine-core/jasmine.js" does not match any file.
12 05 2016 10:06:58.489:WARN [watcher]: Pattern "\\\\node_modules\karma-jasmine\lib\boot.js" does not match any file.
12 05 2016 10:06:58.505:WARN [watcher]: Pattern "\\\\node_modules\karma-jasmine\lib\adapter.js" does not match any file.
12 05 2016 10:06:58.508:WARN [watcher]: Pattern "\\\\node_modules\karma-jasmine-html-reporter\src/css/jasmine.css" does not match any file.
12 05 2016 10:06:58.510:WARN [watcher]: Pattern "\\\\node_modules\karma-jasmine-html-reporter\src/lib/html.jasmine.reporter.js" does not match any file.
12 05 2016 10:06:58.513:WARN [watcher]: Pattern "\\\\node_modules\karma-jasmine-html-reporter\src/lib/adapter.js" does not match any file.
```

Anyone can help me out?