test: fix failing test when required

I suspect, though not 100% sure, that this test fails because it was
being required and when so, chokidar is already watching and thus fires
before the config is loaded.

lib/config/index.js

@@ -17,7 +17,7 @@ function reset() {
   rules.reset();
 
   config.dirs = [];
-  config.options = { ignore: [], watch: [] };
+  config.options = { ignore: [], watch: [], monitor: [] };
   config.lastStarted = 0;
   config.loaded = [];
 }