Add support for Edge on Windows 10

[nickserv]

Fixes #13. This uses my karma-edge-launcher plugin. Since Edge is a UWP app and not a traditional exe file, this locates a launcher (edge-launcher) instead of the browser itself.

Notes

• Because the launcher would be found on operating systems other than Windows 10 (since it's included in node_modules), I had to add some extra code to index.js to ignore Edge on older versions of Windows and other operating systems.
• Windows Server doesn't include Edge yet (but they're working on it in technical previews). This could be a problem if the plugin is run on Windows Server 2016 and os.release() reports 10.x. It's also worth noting that AppVeyor is using Windows Server.
• karma-edge-launcher is still in development.

[nickserv]

The failing Travis build is giving me this error:

01 11 2016 09:53:55.440:ERROR [launcher]: No binary for Chrome browser on your platform.
  Please, set "CHROME_BIN" env variable.

It seems to be isolated to Travis, since grunt demo passes for me locally on Windows 10 and macOS Sierra. I wonder if my Travis build is missing some environment variables because it's from a fork.

[LitixThomas]

Hi,

it works so far. But the "Edge Browser" doesn't close automatically after the test like Chrome or Firefox. Is there a solution?

Thomas

[nickserv]

This is a known bug with karma-edge-launcher. It relies on edge-launcher which does not seem to close Edge after the calling process is killed (see MicrosoftEdge/edge-launcher#21).

By the way, I would appreciate help on fixing the Travis error about missing CHROME_BIN if you have any ideas.

[nickserv]

Thanks for merging!

[LitixThomas]

You are welcome