Do not re-assign

lib/app.js

@@ -26,12 +26,12 @@ var LamassuConfig = require('lamassu-config');
 var routes = require('./routes');
 
 module.exports = function (options) {
-  var connectionString = options.postgres;
   var app = express();
+  var connectionString;
   var server;
   var config;
 
-  connectionString = connectionString ||
+  connectionString = options.postgres ||
                      'postgres://lamassu:lamassu@localhost/lamassu';
 
   config = new LamassuConfig(connectionString);