[fix] path to default skin in bower.json

Author: AlexKlimenkov

bower.json

@@ -5,7 +5,7 @@
   "description": "JavaScript event calendar. Allows to manage events and appointments in different views",
   "main": [
     "codebase/dhtmlxgantt.js",
-    "skins/dhtmlxgantt_terrace.css"
+    "codebase/dhtmlxgantt.css"
   ],
   "keywords": [
     "calendar",