When value is null, don't try to convert to Date, instead just leave it

lib/dialects/sqlite/query.js

@@ -91,7 +91,10 @@ module.exports = (function() {
         results = results.map(function(result) {
           for (var name in result) {
             if (result.hasOwnProperty(name) && (metaData.columnTypes[name] === 'DATETIME')) {
-              result[name] = new Date(result[name]+'Z'); // Z means UTC
+              var val = result[name];
+              if(val !== null) {
+                result[name] = new Date(val+'Z'); // Z means UTC
+              }
             }
           }
           return result