updated file schema to reference snippit schema

Author: smeidan

lib/models/file.js

@@ -13,7 +13,7 @@ var FileSchema = new Schema({
   filePath: String,
   contents: String,
   dependencies: [],
-  snippitRatings: {} // key will be name of method, value will be array of snippits
+  _snippitIds: [Schema.Types.ObjectId]
 });
 
 FileSchema.plugin(textSearch);