Add test description to test details for ExtentITestListenerClassAdapter

[mtorres10]

With current behavior of adapter test description is not displayed for each test when using ExtentITestListenerClassAdapter. This commits adds the following functionality:

• Add test description to test details for ExtentITestListenerClassAdapter. If there is no description for the test, default value for details will be used (Test passed,Test failed or Test skipped)
• Add test description via info log when test result has a throwable. When a throwable is logged it overwrites the test details, therefore the current approach is to add another log to display the test description. @anshooarora Is there a way to have both a code/throwable and plain text on details column?
• Add a couple of tests specific for description

This will probably address issue #20

Screenshot for results:

[Phildor92]

Can this PR be merged?