Update README skip list for systems supported

Resolves  openbmc/openbmc-test-automation#614

Change-Id: I675f6f9a4b351e0b38155324d52d35adde13ec0f
Signed-off-by: George Keishing <gkeishin@in.ibm.com>
diff --git a/README.md b/README.md
index 62052f0..aa9de2e 100755
--- a/README.md
+++ b/README.md
@@ -85,9 +85,15 @@
     No preset environment variables, the entire test suite for a barreleye system
     $ OPENBMC_HOST=x.x.x.x tox -e barreleye -- tests
 
+    Default CI test bucket list:
     No preset environment variables, the entire test suite excluding test
     cases using argument file.
     $ OPENBMC_HOST=x.x.x.x tox -e barreleye -- --argumentfile test_lists/skip_test tests
+
+    Exclude test list for supported systems:
+    Barrleye:  test_lists/skip_test_barreleye
+    Palmetto:  test_lists/skip_test_palmetto
+    Witherspoon:  test_lists/skip_test_witherspoon
 ```
 
 It can also be run by passing variables from the cli...