Update the README again. :lipstick:
diff --git a/acceptance/README.md b/acceptance/README.md
index 1e86c9f..3199837 100644
--- a/acceptance/README.md
+++ b/acceptance/README.md
@@ -29,7 +29,7 @@
 |`OS_TENANT_NAME`|Your API tenant name|
 |`OS_TENANT_ID`|Your API tenant ID|
 |`RS_USERNAME`|Your Rackspace username|
-|`RS_APIKEY`|Your Rackspace API key|
+|`RS_API_KEY`|Your Rackspace API key|
 
 #### General