TINKERPOP-1390 Lowered threshold for failure of this test.

This test was failing randomly on certain systems. Unsure if the new threshold will prevent the failures, but decided to start high with the setting rather than low. CTR

gremlin-core/src/test/java/org/apache/tinkerpop/gremlin/process/traversal/strategy/TraversalStrategyPerformanceTest.java

@@ -51,7 +51,7 @@ protected int getClockRuns() {
      * original traversal. Default is 100.
      */
     protected double getAssertionPercentile() {
-        return 100.0;
+        return 95.0;
     }
 
     protected abstract Class<? extends TraversalStrategy> getStrategyUnderTest();