Use powermock 1.6.4

Author: rodrigc

pom.xml

@@ -40,7 +40,7 @@
 
   <properties>
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-    <powermock.version>1.4.8</powermock.version>
+    <powermock.version>1.6.4</powermock.version>
   </properties>
 
   <repositories>