Fix typo: should be lowercase T for True

Author: Jing Dong

config/config_sample.yml

@@ -149,7 +149,7 @@ dev: &dev
 test:
     <<: *dev
     index_endpoint: https://indexstaging-docker.dotcloud.com
-    standalone: True
+    standalone: true
     storage_path: _env:STORAGE_PATH:./tmp/test
 
 # To specify another flavor, set the environment variable SETTINGS_FLAVOR