Merge pull request #42 from keen/FIX-deepExtend-undefined-bug

Drop properties with undefined values

.travis.yml

@@ -1,6 +1,6 @@
 language: node_js
 node_js:
-  - "0.10"
+  - "5.1"
 branches:
   only:
     - master

dist/keen-tracking.js

@@ -787,7 +787,7 @@ function deepExtend(target){
         if ('undefined' !== typeof target[prop] && 'object' === typeof arguments[i][prop] && arguments[i][prop] !== null) {
           deepExtend(target[prop], clone(arguments[i][prop]));
         }
-        else {
+        else if (arguments[i][prop] !== undefined) {
           target[prop] = clone(arguments[i][prop]);
         }
       }

lib/utils/deepExtend.js

@@ -18,7 +18,7 @@ function deepExtend(target){
           deepExtend(target[prop], clone(arguments[i][prop]));
         }
         // Otherwise just copy it over...
-        else {
+        else if (arguments[i][prop] !== undefined) {
           target[prop] = clone(arguments[i][prop]);
         }
       }