Correct logging_context_format_string for Heat

We should use "tenant" and "user" instead of "project_name" and
"user_name" by calling setup_colorized_logging with these parameters.

Change-Id: I47820c890bf4585e7c8f64c41f48d7576ca56862
Closes-Bug: 1237314
diff --git a/lib/heat b/lib/heat
index ff9473e..8acadb4 100644
--- a/lib/heat
+++ b/lib/heat
@@ -86,7 +86,7 @@
     iniset $HEAT_CONF DEFAULT use_syslog $SYSLOG
     if [ "$LOG_COLOR" == "True" ] && [ "$SYSLOG" == "False" ]; then
         # Add color to logging output
-        setup_colorized_logging $HEAT_CONF DEFAULT
+        setup_colorized_logging $HEAT_CONF DEFAULT tenant user
     fi
 
     # keystone authtoken