Move 'use strict' to file level

Change-Id: I1f0dae4aa168e77c112bcd3688c98b84e4ce5f36
diff --git a/dev/js/src/api.js b/dev/js/src/api.js
index 8eeedf4..75a4e68 100644
--- a/dev/js/src/api.js
+++ b/dev/js/src/api.js
@@ -1,5 +1,6 @@
+"use strict";
+
 define(['util'], function () {
-  "use strict";
 
   // TODO:
   // - https://github.com/honza/140medley/blob/master/140medley.js