modify inigo tests to clean up mounted test volumes after unmount [#118660173](https://www.pivotaltracker.com/story/show/118660173)
modify inigo tests to clean up mounted test volumes after unmount
[#118660173](https://www.pivotaltracker.com/story/show/118660173)

Signed-off-by: Julian Hjortshoj <a84af1ff40fcfa3bc4844358f827e17a8b38c426@emc.com>

cloudfoundry-incubator/inigo