Add tests for identity endpoints

Change-Id: If15cc74fafbbe52fa86aa353f2598aa31daf0695
Closes-Bug: #1319450
replace string format arguments with function parameters

There are files containing string format arguments inside
logging messages. Using logging function parameters should
be preferred.

Change-Id: Ic749ac9eb55564ed631d57055a5a4dfc3aebd169
Merge "replace string format arguments with function parameters"
Merge "Add tests for identity endpoints"