Resolved Exception with GraphSummaryConfig #19

    java.lang.AssertionError: expected:<true> but was:<null>
        at org.junit.Assert.fail(Assert.java:93)
        at org.junit.Assert.failNotEquals(Assert.java:647)
        at org.junit.Assert.assertEquals(Assert.java:128)
        at org.junit.Assert.assertEquals(Assert.java:147)
        at org.sindice.graphsummary.cascading.TestGraphSummaryConfig.testBoolean(TestGraphSummaryConfig.java:72)