tests: correct cleanup for '/target' location of artefacts
tests: correct cleanup for '/target' location of artefacts

silasdavis/burrow,silasdavis/burrow,benjaminbollen/burrow,silasdavis/burrow,benjaminbollen/eris-db,eris-ltd/eris-db,eris-ltd/eris-db,benjaminbollen/burrow,benjaminbollen/eris-db