update test library versions (#481)

Author: elharo

pom.xml

@@ -116,12 +116,12 @@
       <dependency>
         <groupId>junit</groupId>
         <artifactId>junit</artifactId>
-        <version>4.8.2</version>
+        <version>4.12</version>
       </dependency>
       <dependency>
         <groupId>com.google.truth</groupId>
         <artifactId>truth</artifactId>
-        <version>0.40</version>
+        <version>0.42</version>
         <scope>test</scope>
       </dependency>
       <dependency>
@@ -232,7 +232,7 @@
       <dependency>
         <groupId>org.mockito</groupId>
         <artifactId>mockito-all</artifactId>
-        <version>1.9.0</version>
+        <version>1.10.19</version>
       </dependency>
       <dependency>
         <groupId>javax.jdo</groupId>