updated release notes

Author: arcuri82

release_notes.md

@@ -8,6 +8,7 @@ Under development in `master` branch.
   This is to avoid generating single output test files with thousands of tests.
   Those will be split among different test suite files, with each containing at most _maxTestsPerTestSuite_ tests. 
    A negative value means no constraint is applied (i.e., old behavior).  
+- If no authentication information is set up, or if it was done just for a single user, then now we issue descriptive warning messages with links to the documentation on how to set up authentication info. 
 
 ### Fixed Bugs