Redfish cheatsheet: Add viewing session

Change-Id: I5586e230801824e28368941834c5b193c0c6fff8
Signed-off-by: Gunnar Mills <gmills@us.ibm.com>
diff --git a/REDFISH-cheatsheet.md b/REDFISH-cheatsheet.md
index 3d65f2a..cbf2a48 100644
--- a/REDFISH-cheatsheet.md
+++ b/REDFISH-cheatsheet.md
@@ -42,6 +42,13 @@
 
 ---
 
+## View sessions
+```
+curl -k -H "X-Auth-Token: $token" https://${bmc}/redfish/v1/SessionService/Sessions
+```
+
+---
+
 ## Host power
 Host soft power off:
 ```