Updated wercker test step

wercker.yml

@@ -39,8 +39,8 @@ build:
     - script:
         name: create packages
         code: |
-          mkdir dist
-          touch dist/my_file.txt
+          mkdir $WERCKER_SOURCE_DIR/dist
+          touch $WERCKER_SOURCE_DIR/dist/my_file.txt
 
     - s3sync:
         key-id: $AWS_S3_KEY