update start script

previously the if statement was not working, fixed by switching to bash as script processor. Also added switches to set up bash strict mode, so it fails on unset variables and exits on any failures

Author: nvdk

start.sh

@@ -1,7 +1,6 @@
-#! /usr/bin/env sh
-set -e
-
-if [ $MODE = "development" ]; then 
+#! /usr/bin/env bash
+set -eu
+if [ ${MODE:-""} == "development" ]; then 
     exec python web.py
 else 
     exec gunicorn -k egg:meinheld#gunicorn_worker -c "$GUNICORN_CONF" "$APP_MODULE"