don't capture logs directly from stdout

previously in run_app_paas.sh, we captured stdout from the app and
piped that into the log file. However, this came up with a bunch of
problems, mainly:

* exceptions with stack traces often weren't formatted properly,
  and kibana could not parse them
* celery logs were duplicated - we'd collect both the json logs and
  the human readable stdout logs.

instead, with the updated utils library, we can use that to log json
straight to the appropriate directory directly.

scripts/run_app_paas.sh

@@ -52,11 +52,9 @@ function on_exit {
   kill 0
 }
 
-function start_appplication {
-  exec "$@" 2>&1 | while read line; do echo $line; echo $line >> /home/vcap/logs/app.log.`date +%Y-%m-%d`; done &
-  LOGGER_PID=$!
+function start_application {
+  exec "$@" &
   APP_PID=`jobs -p`
-  echo "Logger process pid: ${LOGGER_PID}"
   echo "Application process pid: ${APP_PID}"
 }
 
@@ -69,7 +67,6 @@ function start_aws_logs_agent {
 function run {
   while true; do
     kill -0 ${APP_PID} 2&>/dev/null || break
-    kill -0 ${LOGGER_PID} 2&>/dev/null || break
     kill -0 ${AWSLOGS_AGENT_PID} 2&>/dev/null || start_aws_logs_agent
     sleep 1
   done
@@ -84,7 +81,7 @@ trap "on_exit" EXIT
 configure_aws_logs
 
 # The application has to start first!
-start_appplication "$@"
+start_application "$@"
 
 start_aws_logs_agent