Stop reading .babelrc files.

If a `.babelrc` file is present, it is being read, and the settings merged with the ones we specify for tests. We don't want that.

Reference:
 http://babeljs.io/docs/usage/options/

Author: jamestalmage

lib/test-worker.js

@@ -51,7 +51,8 @@ var send = require('./send');
 
 // if generators are not supported, use regenerator
 var options = {
-	sourceMaps: true
+	sourceMaps: true,
+	babelrc: false
 };
 
 // check if test files required ava and show error, when they didn't