made test_urdf independent from ros package urdfdom by using liburdfdom-dev  directly as its recommended in the package description of urdfdom
made test_urdf independent from ros package urdfdom by using liburdfdom-dev  directly as its recommended in the package description of urdfdom
Merge pull request #232 from arne48/hydro-devel

Making test_urdf independent from urdfdom ros package to avoid test from failing