test failing in travis Batcher should batch based on batch size

```
whisk.core.database.test.BatcherTests > Batcher should batch based on batch size FAILED
org.scalatest.exceptions.TestFailedException: Queue(2) had size 1 instead of expected size 2
at org.scalatest.MatchersHelper$.indicateFailure(MatchersHelper.scala:340)
at org.scalatest.Matchers$ResultOfHaveWordForExtent.size(Matchers.scala:2707)
at whisk.core.database.test.BatcherTests$$anonfun$2.apply(BatcherTests.scala:70)
at whisk.core.database.test.BatcherTests$$anonfun$2.apply(BatcherTests.scala:47)
at org.scalatest.OutcomeOf$class.outcomeOf(OutcomeOf.scala:85)
at org.scalatest.OutcomeOf$.outcomeOf(OutcomeOf.scala:104)
at org.scalatest.Transformer.apply(Transformer.scala:22)
at org.scalatest.Transformer.apply(Transformer.scala:20)
at org.scalatest.FlatSpecLike$$anon$1.apply(FlatSpecLike.scala:1682)
at org.scalatest.TestSuite$class.withFixture(TestSuite.scala:196)
at org.scalatest.FlatSpec.withFixture(FlatSpec.scala:1685)
at org.scalatest.FlatSpecLike$class.invokeWithFixture$1(FlatSpecLike.scala:1679)
at org.scalatest.FlatSpecLike$$anonfun$runTest$1.apply(FlatSpecLike.scala:1692)
at org.scalatest.FlatSpecLike$$anonfun$runTest$1.apply(FlatSpecLike.scala:1692)
at org.scalatest.SuperEngine.runTestImpl(Engine.scala:289)
at org.scalatest.FlatSpecLike$class.runTest(FlatSpecLike.scala:1692)
at org.scalatest.FlatSpec.runTest(FlatSpec.scala:1685)
at org.scalatest.FlatSpecLike$$anonfun$runTests$1.apply(FlatSpecLike.scala:1750)
at org.scalatest.FlatSpecLike$$anonfun$runTests$1.apply(FlatSpecLike.scala:1750)
at org.scalatest.SuperEngine$$anonfun$traverseSubNodes$1$1.apply(Engine.scala:396)
at org.scalatest.SuperEngine$$anonfun$traverseSubNodes$1$1.apply(Engine.scala:384)
at scala.collection.immutable.List.foreach(List.scala:392)
at org.scalatest.SuperEngine.traverseSubNodes$1(Engine.scala:384)
at org.scalatest.SuperEngine.org$scalatest$SuperEngine$$runTestsInBranch(Engine.scala:373)
at org.scalatest.SuperEngine$$anonfun$traverseSubNodes$1$1.apply(Engine.scala:410)
at org.scalatest.SuperEngine$$anonfun$traverseSubNodes$1$1.apply(Engine.scala:384)
at scala.collection.immutable.List.foreach(List.scala:392)
at org.scalatest.SuperEngine.traverseSubNodes$1(Engine.scala:384)
at org.scalatest.SuperEngine.org$scalatest$SuperEngine$$runTestsInBranch(Engine.scala:379)
at org.scalatest.SuperEngine.runTestsImpl(Engine.scala:461)
at org.scalatest.FlatSpecLike$class.runTests(FlatSpecLike.scala:1750)
at org.scalatest.FlatSpec.runTests(FlatSpec.scala:1685)
at org.scalatest.Suite$class.run(Suite.scala:1147)
at org.scalatest.FlatSpec.org$scalatest$FlatSpecLike$$super$run(FlatSpec.scala:1685)
at org.scalatest.FlatSpecLike$$anonfun$run$1.apply(FlatSpecLike.scala:1795)
at org.scalatest.FlatSpecLike$$anonfun$run$1.apply(FlatSpecLike.scala:1795)
at org.scalatest.SuperEngine.runImpl(Engine.scala:521)
at org.scalatest.FlatSpecLike$class.run(FlatSpecLike.scala:1795)
at whisk.core.database.test.BatcherTests.org$scalatest$BeforeAndAfterAll$$super$run(BatcherTests.scala:36)
at org.scalatest.BeforeAndAfterAll$class.liftedTree1$1(BeforeAndAfterAll.scala:213)
at org.scalatest.BeforeAndAfterAll$class.run(BeforeAndAfterAll.scala:210)
at whisk.core.database.test.BatcherTests.run(BatcherTests.scala:36)
```