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.

app/cloudfoundry_config.py

@@ -18,7 +18,7 @@ def set_config_env_vars(vcap_services):
 
     vcap_application = json.loads(os.environ['VCAP_APPLICATION'])
     os.environ['NOTIFY_ENVIRONMENT'] = vcap_application['space_name']
-    os.environ['LOGGING_STDOUT_JSON'] = '1'
+    os.environ['NOTIFY_LOG_PATH'] = '/home/vcap/logs/app.log'
 
     # Notify common config
     for s in vcap_services['user-provided']:

app/config.py

@@ -95,7 +95,6 @@ class Config(object):
 
     # Logging
     DEBUG = False
-    LOGGING_STDOUT_JSON = os.getenv('LOGGING_STDOUT_JSON') == '1'
 
     ###########################
     # Default config values ###
@@ -106,7 +105,7 @@ class Config(object):
     AWS_REGION = 'eu-west-1'
     INVITATION_EXPIRATION_DAYS = 2
     NOTIFY_APP_NAME = 'api'
-    NOTIFY_LOG_PATH = '/var/log/notify/application.log'
+    NOTIFY_LOG_PATH = None
     SQLALCHEMY_COMMIT_ON_TEARDOWN = False
     SQLALCHEMY_RECORD_QUERIES = True
     SQLALCHEMY_TRACK_MODIFICATIONS = True
@@ -277,6 +276,7 @@ class Config(object):
 ######################
 
 class Development(Config):
+    NOTIFY_LOG_PATH = 'application.log'
     SQLALCHEMY_ECHO = False
     NOTIFY_EMAIL_DOMAIN = 'notify.tools'
     CSV_UPLOAD_BUCKET_NAME = 'development-notifications-csv-upload'