BUG-576: fixed test sources loading in YangModuleInfoCompilationTest.

Fixed test to parse File sources with relative test.

Change-Id: I4af05166a2c26cf4a3f673b1651ac28c717dd43e
Signed-off-by: Martin Vitez <mvitez@cisco.com>
Merge "BUG-576: fixed test sources loading in YangModuleInfoCompilationTest."