Failing tests on build on master

Running org.apache.zeppelin.notebook.repo.VFSNotebookRepoTest
SLF4J: Class path contains multiple SLF4J bindings.
SLF4J: Found binding in [jar:file:/home/travis/build/apache/incubator-zeppelin/zeppelin-interpreter/target/zeppelin-interpreter-0.6.0-incubating-SNAPSHOT.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/home/travis/build/apache/incubator-zeppelin/zeppelin-interpreter/target/lib/slf4j-log4j12-1.7.10.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/home/travis/.m2/repository/org/slf4j/slf4j-log4j12/1.7.10/slf4j-log4j12-1.7.10.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: See http://www.slf4j.org/codes.html#multiple_bindings for an explanation.
SLF4J: Actual binding is of type [org.slf4j.impl.Log4jLoggerFactory]
01:01:42,914  INFO org.apache.zeppelin.conf.ZeppelinConfiguration:98 - Load configuration from file:/home/travis/build/apache/incubator-zeppelin/zeppelin-zengine/target/test-classes/zeppelin-site.xml
01:01:43,021  INFO org.apache.zeppelin.interpreter.InterpreterFactory:602 - Create repl org.apache.zeppelin.interpreter.mock.MockInterpreter1 from null
01:01:43,037  INFO org.apache.zeppelin.interpreter.InterpreterFactory:190 - Interpreter setting group mock1 : id=2B9JXP4T1, name=mock1
01:01:43,038  INFO org.apache.zeppelin.interpreter.InterpreterFactory:193 -   className = org.apache.zeppelin.interpreter.mock.MockInterpreter1
01:01:43,053  INFO org.apache.commons.vfs2.impl.StandardFileSystemManager:138 - Using "/tmp/vfs_cache" as temporary files store.
01:01:43,234  INFO org.apache.zeppelin.notebook.Paragraph:191 - run paragraph 20151218-010143_2061221824 using mock1 org.apache.zeppelin.interpreter.LazyOpenInterpreter@b926d29
Tests run: 1, Failures: 0, Errors: 1, Skipped: 0, Time elapsed: 1.522 sec <<< FAILURE! - in org.apache.zeppelin.notebook.repo.VFSNotebookRepoTest
testSaveNotebook(org.apache.zeppelin.notebook.repo.VFSNotebookRepoTest)  Time elapsed: 1.398 sec  <<< ERROR!
java.io.IOException: Unable to delete directory /tmp/ZeppelinLTest_1450400502897/notebook/2B8777MR2.
	at org.apache.commons.io.FileUtils.deleteDirectory(FileUtils.java:1541)
	at org.apache.commons.io.FileUtils.forceDelete(FileUtils.java:2270)
	at org.apache.commons.io.FileUtils.cleanDirectory(FileUtils.java:1653)
	at org.apache.commons.io.FileUtils.deleteDirectory(FileUtils.java:1535)
	at org.apache.commons.io.FileUtils.forceDelete(FileUtils.java:2270)
	at org.apache.commons.io.FileUtils.cleanDirectory(FileUtils.java:1653)
	at org.apache.commons.io.FileUtils.deleteDirectory(FileUtils.java:1535)
	at org.apache.zeppelin.notebook.repo.VFSNotebookRepoTest.tearDown(VFSNotebookRepoTest.java:88)

Tests in error: 
  VFSNotebookRepoTest.tearDown:88 » IO Unable to delete directory /tmp/ZeppelinL...

[INFO] Zeppelin: Zengine .................................. FAILURE [  9.024 s]
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE