Enable CORS so sites can use directly in JS. Fixes #43.

server/app.js

@@ -18,6 +18,12 @@ app.use(express.cookieParser());
 app.use(express.static(__dirname + '/public'));
 app.use(express.json());
 app.use(express.urlencoded());
+app.use(function(req, res, next) {
+  // Enable CORS so sites can use the API directly in JS.
+  res.header('Access-Control-Allow-Origin', '*');
+  res.header('Access-Control-Allow-Headers', 'Origin, X-Requested-With, Content-Type, Accept');
+  next();
+});
 
 // Enable log messages when sending texts.
 text.debug(true);