[FirstRun] Rewrite to use switch for index require, generic stub

src/firstRun/darwin.js

@@ -1 +0,0 @@
-module.exports = require('./stub');

src/firstRun/index.js

@@ -1,2 +1,9 @@
-// Stub for now at least
-module.exports = require('./' + process.platform);
+// Depends on platform
+switch (process.platform) {
+  case 'win32':
+    module.exports = require('./win32.js');
+    break;
+
+  default:
+    module.exports = require('./stub.js');
+}

src/firstRun/linux.js

@@ -1 +0,0 @@
-module.exports = require('./stub');