Review fixes

Author: JonasKunz

libs/exponential-histogram/src/test/java/org/elasticsearch/exponentialhistogram/ExponentialScaleUtilsTests.java

@@ -23,6 +23,8 @@
 
 import ch.obermuhlner.math.big.BigDecimalMath;
 
+import org.elasticsearch.test.ESTestCase;
+
 import java.math.BigDecimal;
 import java.math.MathContext;
 import java.math.RoundingMode;
@@ -47,7 +49,7 @@
 import static org.hamcrest.Matchers.lessThan;
 import static org.hamcrest.Matchers.lessThanOrEqualTo;
 
-public class ExponentialScaleUtilsTests extends ExponentialHistogramTestCase {
+public class ExponentialScaleUtilsTests extends ESTestCase {
 
     public void testMaxIndex() {
         assertThat(getMaximumScaleIncrease(MAX_INDEX), equalTo(0));