upgraded hppc to 0.7.2

Author: Matt Darwin

java/vector/pom.xml

@@ -49,7 +49,7 @@
     <dependency>
       <groupId>com.carrotsearch</groupId>
       <artifactId>hppc</artifactId>
-      <version>0.7.1</version>
+      <version>0.7.2</version>
     </dependency>
     <dependency>
       <groupId>org.apache.commons</groupId>