fix(Launcher): do not detach child process on windows (#2081)

Fixes #2053.

lib/Launcher.js

@@ -107,7 +107,10 @@ class Launcher {
         chromeExecutable,
         chromeArguments,
         {
-          detached: true,
+          // On non-windows platforms, `detached: false` makes child process a leader of a new
+          // process group, making it possible to kill child process tree with `.kill(-pid)` command.
+          // @see https://nodejs.org/api/child_process.html#child_process_options_detached
+          detached: process.platform !== 'win32',
           env: options.env || process.env,
           stdio
         }