Ticket 48303 - Fix lib389 broken tests - backend_test
    
    Description: Fix the imports to the correct ones.
                 Add Red Hat copyright block.
                 Remove "Created on" block, because git contains
                 this information.
                 Add a logging.
                 Add docstrings to the all tests.
                 Divide the delete test case into two: for valid
                 and invalid cases.
                 Fix expected exception assertions within the create
                 and the delete_invalid test cases.
                 Add assert statement to the toSuffix test case.
                 Refactore code to the pytest compatibility.
    
    https://fedorahosted.org/389/ticket/48303
    
    Review by: mreynolds (Thanks!)