Add info about Heat w/ AppCreds

cli/README.md

@@ -17,7 +17,8 @@ it is a form of token-based authentication providing easy and secure access with
   <div style="border-width:0;border-left:5px solid #b8d6f4;background-color:rgba(228,240,251,0.3);margin:20px 0;padding:10px 20px;font-size:15px;">
     <strong>Notice:</strong><br/>
     If you decide to select specific roles, you should always include at least the <strong>member</strong> role.
-    If you are planning to use the orchestration API, add the <strong>heat_stack_owner</strong> role as well.
+    If you are planning to use the orchestration API, add the <strong>heat_stack_owner</strong> role as well and
+    check <strong>Unrestricted</strong>.
   </div>
 
 3. Download provided configuration files for the OpenStack CLI client.