maven build error running tests

-------------------------------------------------------
T E S T S
-------------------------------------------------------
Running eu.iksproject.kres.reasoners.KReSRunReasonerTest
:::::::::::::::: consistency check true
:::::::::::::::: consistency check true
:::::::::::::::: consistency check true
:::::::::::::::: consistency check true
Tests run: 5, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 2.259 sec
Running eu.iksproject.kres.reasoners.KReSRunSPARQLTest
Tests run: 4, Failures: 0, Errors: 4, Skipped: 0, Time elapsed: 0.145 sec <<< FAILURE!
Running eu.iksproject.kres.reasoners.KReSRunRulesTest
Tests run: 4, Failures: 0, Errors: 4, Skipped: 0, Time elapsed: 0.074 sec <<< FAILURE!

Results :

Tests in error:
testGetSPARQLprefix(eu.iksproject.kres.reasoners.KReSRunSPARQLTest)
testAddSPARQLprefix(eu.iksproject.kres.reasoners.KReSRunSPARQLTest)
testRemoveSPARQLprefix(eu.iksproject.kres.reasoners.KReSRunSPARQLTest)
testRunSPARQL(eu.iksproject.kres.reasoners.KReSRunSPARQLTest)
testRunRulesReasoner_OWLOntology_1(eu.iksproject.kres.reasoners.KReSRunRulesTest)
testRunRulesReasoner_0args_1(eu.iksproject.kres.reasoners.KReSRunRulesTest)
testRunRulesReasoner_OWLOntology_2(eu.iksproject.kres.reasoners.KReSRunRulesTest)
testRunRulesReasoner_0args_2(eu.iksproject.kres.reasoners.KReSRunRulesTest)

Tests run: 13, Failures: 0, Errors: 8, Skipped: 0

[INFO] ------------------------------------------------------------------------
[ERROR] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] There are test failures.