Flaky test - startUpWithAuthenticationEnable()

Caused by: com.google.gson.JsonSyntaxException: duplicate key: 2C6EDDAHM
	at com.google.gson.internal.bind.MapTypeAdapterFactory$Adapter.read(MapTypeAdapterFactory.java:191)
	at com.google.gson.internal.bind.MapTypeAdapterFactory$Adapter.read(MapTypeAdapterFactory.java:146)
	at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.read(ReflectiveTypeAdapterFactory.java:93)
	at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.read(ReflectiveTypeAdapterFactory.java:172)
	at com.google.gson.Gson.fromJson(Gson.java:791)
	at com.google.gson.Gson.fromJson(Gson.java:757)
	at com.google.gson.Gson.fromJson(Gson.java:706)
	at com.google.gson.Gson.fromJson(Gson.java:678)
	at org.apache.zeppelin.interpreter.InterpreterFactory.loadFromFile(InterpreterFactory.java:387)
	at org.apache.zeppelin.interpreter.InterpreterFactory.init(InterpreterFactory.java:248)
	at org.apache.zeppelin.interpreter.InterpreterFactory.<init>(InterpreterFactory.java:165)
	at org.apache.zeppelin.interpreter.InterpreterFactory.<init>(InterpreterFactory.java:138)
	at org.apache.zeppelin.server.ZeppelinServer.<init>(ZeppelinServer.java:135)
	... 35 more

...
...

Results :

Tests in error: 
  NotebookSecurityRestApiTest.init:49->AbstractTestRestApi.startUpWithAuthenticationEnable:229->AbstractTestRestApi.start:179 » Runtime

Tests run: 53, Failures: 0, Errors: 1, Skipped: 0

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-surefire-plugin:2.17:test (default-test) on project zeppelin-server: There are test failures.
[ERROR] 
[ERROR] Please refer to /home/travis/build/apache/zeppelin/zeppelin-server/target/surefire-reports for the individual test results.
[ERROR] -> [Help 1]
[ERROR] 
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR] 
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoFailureException
[ERROR] 
[ERROR] After correcting the problems, you can resume the build with the command
[ERROR]   mvn <goals> -rf :zeppelin-server