Adding entry to suite_scheduler.ini for nightly stress run.

BUG=None
TEST=Ran 'suite_scheduler.py --sanity'

Change-Id: Ibe77c14b479b7edb00ad872ccc6611c3681eeb16
Reviewed-on: https://chromium-review.googlesource.com/198907
Reviewed-by: Kris Rambish <krisr@chromium.org>
Reviewed-by: Alex Miller <milleral@chromium.org>
Commit-Queue: Yusuf Mohsinally <mohsinally@chromium.org>
Tested-by: Yusuf Mohsinally <mohsinally@chromium.org>
diff --git a/suite_scheduler.ini b/suite_scheduler.ini
index 004ed6a..e851947 100644
--- a/suite_scheduler.ini
+++ b/suite_scheduler.ini
@@ -328,3 +328,8 @@
 branch_specs: >=R34
 pool: wificell
 
+[NightlyStress]
+run_on: nightly
+suite: stress
+branch_specs: >=R36
+pool: stress