New base class to declare test cases and tests to the node option

This patch refactors the tests suite to use a base class to declare test cases
just using a class declaration, the existing test class was modified to use it
and new tests are using it as well.

These tests verify the XML generated when the 'node' option is set and
when it's absent.

Change-Id: Iddcdd63e0ab7c459f6513b1d1ebf19e19a362c1d
Added support for Git shallow clone parameter

Change-Id: Ia0251f25ff22fff10fe53ba6bf54f0e9072210fd
Merge "New base class to declare test cases and tests to the node option"
Merge "Added support for Git shallow clone parameter"