add unit tests (issue #7)

This version introduces multiple enhancements:

test with creation data from stdClass object (automatically detect that given data is stdClass)

Details of additions/deletions below:
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Modified:   Test/ObjectTest.php
            -- Added --
                testCreationWithStdClassData allow to create object with given stdClass object
            -- Updated --
                _exampleStdData added logic to create stdCalss object